Biden’s remarks came on the same day that Democratic lawmakers raised new concerns about foreign influence operations in a letter to the FBI requesting fresh counterintelligence briefings ahead of the election. And they come as Biden’s campaign advisers have begun speaking out with fresh urgency about what they fear could become a serious threat.

“Despite the exposure of Russia’s malign activities by the U.S. Intelligence Community, law enforcement agencies, and bipartisan Congressional committees, the Kremlin has not halted its efforts to interfere in our democracy,” Biden’s statement reads. “Congress passed with an overwhelming bipartisan majority the Countering America’s Adversaries Through Sanctions Act of 2017. The Trump administration has thus far failed to make adequate use of these authorities to counter and deter foreign election interference.”

The former vice president’s comments reflect a growing concern not only about President Donald Trump’s unwillingness to commit to not accepting foreign help in the election, but also about what the former vice president’s campaign and bipartisan members of Congress see as an escalating disinformation campaign emerging out of Ukraine, said people familiar with his thinking.

They point to late last month, when a former student of a top Russian spy academy convened a press conference to unveil what he called “facts of international corruption and treason at the highest state level.”

In a well-choreographed, 75-minute presentation set against the logo of Russian news agency Interfax—and overlaid with English subtitles by the time it was posted on YouTube—Ukrainian lawmaker Andrey Derkach accused Biden, his son and members of his team of an elaborate conspiracy to steal hundreds of millions of dollars from Ukraine through bribery and extortion.

Many of the misconduct accusations against Biden, which were examined during President Donald Trump’s impeachment trial last year, have been debunked; others remain unsubstantiated. But the former vice president’s advisers are bracing for an onslaught of accusations that, they say, recall Russia’s efforts to damage Hillary Clinton and the Democrats in 2016.

Internal divisions remain over how to handle what some current and former U.S. officials say bears the hallmarks of a foreign influence operation. But the Biden camp believes it at least requires constant attention, and has invested significant resources into monitoring the disinformation, according to three people close to the campaign. It has stood up a team that works with the DNC to track misinformation and foreign interference efforts, which is now positioned to quickly flag issues to staff to determine the best response, the people said—though in most cases, that means no overt response at all.

Michael Carpenter, the managing director of the Penn Biden Center for Diplomacy and Global Engagement who now serves as an informal foreign policy adviser to the Biden campaign, said the campaign is “closely monitoring and exposing these methods, and actors, as Russian tools, precisely so that it’s unmistakably clear to the American people, if something fabricated or tampered with or dishonestly presented were to drop later in the campaign, that it's coming from the same people who have been spewing lies and disinformation for months.”

The impact of the Ukrainians’ accusations has so far been minimal; the allegations are byzantine, requiring a familiarity with Kyiv’s oligarch-dominated, cut-throat politics that few Americans possess. During the Democratic primary, Biden weathered Trump’s attacks on his son Hunter’s involvement with a Ukrainian gas company, Burisma; the president’s hamfisted attempts to enlist his Ukrainian counterpart in the effort ultimately led to his impeachment, while the former vice president may have benefited from having the issue litigated in the public arena more than a year out from the general election.

But some close to Biden’s campaign have expressed concern in recent weeks that actors like Derkach are laying the groundwork to hammer Biden on the Ukraine issue using heavily edited or doctored tapes in the waning days and weeks of the election—with the help of Trump, who has signaled he would happily accept foreign dirt on an opponent, and his allies on Capitol Hill, whose investigation of Burisma and the Bidens has at times mirrored Derkach’s accusations.

Recordings of Biden speaking to then-Ukrainian President Petro Poroshenko have already been released by Derkach, whose YouTube video unveiling them has been viewed nearly 300,000 times in the last 3 weeks. The leaked tapes’ provenance is unknown and reveal no new information, but have been used by the Ukrainian to make new, unsubstantiated claims against Biden and Poroshenko.

Derkach, an independent MP who was formerly aligned with Ukraine’s pro-Russia Party of Regions, told POLITICO in a lengthy statement that his press conferences were focused on “international corruption,” and called it “nonsense” that he is trying to interfere in the U.S. election. He also denounced efforts “to tie me to the special services of other countries,” like Russia, and said his critics were trying to discredit him by drawing attention to his studies at Moscow’s FSB academy, formerly known as the Dzerzhinsky Higher School of the KGB.

Derkach’s father, Leonid, was a KGB operative for decades before becoming the head of Ukraine’s security services until he was fired in 2004 over his alleged involvement in a murder plot.

“The main purpose of our activity is pursuing the interests of Ukraine, exposing international corruption, [and] maintaining partnership relations between strategic partners – Ukraine and the USA,” said the younger Derkach, who hired lobbyists earlier this year to set up meetings for him with White House officials and members of “the Senate Foreign Relationship and House of Foreign Affairs Committees.” (He now alleges his U.S. visa has been revoked.)

Derkach was openly hostile to efforts by Ukraine to assist former special counsel Robert Mueller’s investigation of Paul Manafort—Trump’s former campaign chairman who was convicted of bank and tax fraud stemming from his work in Ukraine, where he was also investigated by the country’s National Anti-Corruption Bureau (NABU) over alleged illegal payments. NABU is now one of Derkach’s chief targets.

Meanwhile, Andrii Telizhenko, a former political officer in the Ukrainian Embassy who has also worked with Trump’s former personal lawyer Rudy Giuliani to undermine Biden, told POLITICO in a phone interview on Wednesday that he gave more recorded conversations between Biden and Poroshenko to a third party who will decide whether and how to release them.

“I’m not releasing anything on my own,” Telizhenko said. “I don’t want to interfere in anything. I gave it to a U.S. source and had them decide what to release and what not to release, not to interfere in any political situation in the United States.” He also vehemently denies any allegations that he’s working with the Russians, saying, “I’m not supporting Russia in any way” and “I again see myself as a patriot of Ukraine.”

The Biden campaign is reluctant to address the Ukraine recordings; his aides would prefer to focus on Trump’s handling of the coronavirus, the collapsing U.S. economy and Americans’ concerns about health care than to dignify what they see as scurrilous and misleading attacks. Indeed, in his statement on Monday, Biden said he has “no desire to escalate tensions with Russia or any other country and “would prefer to focus the full energies of my administration on bringing the international community together to fight COVID-19 and the economic pain it has caused, and to tackle other pressing issues of international concern.”

“But if any foreign power recklessly chooses to interfere in our democracy, I will not hesitate to respond as president to impose substantial and lasting costs,” he added.

There is no evidence that Derkach, Artemenko and Telizhenko are working with Russia. And so far, the recordings have drawn little sustained media attention. But some in the Biden camp see tactics that, at a minimum, resemble the Russian playbook; others explicitly accuse the Kremlin of involvement in the accusations.

An informal campaign adviser, who spoke on condition of anonymity to discuss the issue, said they are trying to avoid “the trap that the Russians are clearly trying to lay here.”

Biden and several of his top campaign advisers—including former deputy secretary of state Tony Blinken, former national security adviser Susan Rice and her then-deputy Avril Haines—are more than familiar with Russia’s tactics: They dealt with them firsthand in 2016, when the Obama administration scrambled to respond to the Kremlin’s brazen hacking-and-dumping and disinformation operation, and targeting of electoral infrastructure.

Biden himself has made discouraging foreign interference, both in the U.S. and abroad, a key initiative. He joined the Transatlantic Commission on Election Integrity in 2018, which aims to raise awareness about foreign election meddling and ever-shifting disinformation tactics, and has pledged not to accept foreign help or use stolen or fabricated material to attack his opponents—his campaign has even instructed staffers and volunteers to severely limit their interactions with foreign officials to avoid even the perception of outside interference.

“This is a very deep campaign, with a lot of people who have expertise on Russia and Ukraine and who went through this kind of operation in 2016,” said an informal Biden adviser. “They understand what the Russian government is capable of doing.”

So how are they dealing with it this time around? Quietly and strategically, people close to the campaign said.

“We absolutely need to be monitoring this and we are,” said a third adviser. “And we need to be cognizant that Russia is certainly replaying the 2016 playbook. But the circumstances are slightly different.”

Several advisers and experts pointed to the risk of inadvertently elevating Derkach’s efforts, which are not nearly on the same scale as Russia’s massive effort in 2016, by responding to them publicly.

“We’ve seen that Russian disinformation thrives on throwing dirt into the air and refocusing attention on stories where there is no story,” an informal Biden adviser said. “So we don’t want to play into that game.”

“You don’t want to give these obvious smears and falsehoods any more attention,” another Biden adviser said. But, he acknowledged, “It is hard for U.S. consumers who don’t know as much about Russian intelligence and Ukraine to know where all this is coming from.”

Laura Rosenberger, a former Obama official who now heads the Alliance for Securing Democracy and is a senior fellow at the German Marshall Fund, cautioned that “there’s a real line to walk there, and a constant calculus that needs to be thought through.”

But, she said, “the most important piece for the Biden campaign, from a counter-disinformation perspective, is to have absolute maximum visibility into what’s happening. That includes monitoring what, where, and when something is being pushed, so that when it breaks through that tipping point they can focus on exposure of the operation and debunking it.”

The campaign accordingly picks and chooses its battles: In early June, it forwarded to The Atlantic an inquiry from One America News about tapes the pro-Trump television network said it had obtained of Biden speaking to Poroshenko, viewing the query as an opportunity to expose the effort in a more sympathetic venue. “Is OAN the Leading Edge of Russian Misinformation?” the magazine’s headline read. “The Biden campaign says Trump’s favorite TV network is peddling the Kremlin’s lies.”

Another tactic the Biden campaign has employed: preemptively shaming mainstream media outlets out of covering such accusations in the first place.

During Trump’s impeachment trial last year, which some advisers described to POLITICO as a kind of “trial run” for the Biden campaign’s effort to combat foreign propaganda, senior campaign officials wrote letters to the major news networks including CNN, ABC, and CBS, imploring them to stop booking Trump’s personal lawyer Rudy Giuliani. Derkach met with Giuliani last year in what he said was an effort to fight corruption; the Biden campaign said the former New York mayor instead was seeking to inject “unhinged, unfounded and desperate lies into the national conversation.” Giuliani and Derkach appear to have met again in February of this year for a taping of Giuliani’s podcast.

The campaign also wrote a scathing letter to the New York Times’ executive editor, accusing the paper of participating in a “smear campaign” that elevated conspiracy theories about Biden and his son that had previously been “relegated to the likes of Breitbart, Russian propaganda, and another conspiracy theorist, regular Hannity guest John Solomon.”

Officially, the campaign says it is ready for whatever Trump and “his corrupt international patrons and domestic accomplices,” as a spokesman put it, throw at them in the coming months.

"Donald Trump is the only president in American history who attempted to coerce a foreign nation into smearing the potential general election rival he feared most - getting impeached in the process - or who begged the authoritarian leader of China to bail out his struggling campaign, or who sided with the Russian president over the entirety of the U.S. intelligence community with respect to an attack on our very sovereignty,” Biden campaign spokesman Andrew Bates said in a statement.

“Most tellingly, right now the White House, his campaign, and his Republican allies in Congress will not even respond when asked if they are party to an ongoing foreign influence operation,” he said. “We have always known exactly what to expect, and have always planned to look his corrupt international patrons and domestic accomplices in the eye and burn their smears down.”

Biden’s team is especially concerned that what might seem like relatively harmless attacks now could morph into something more damaging closer to Election Day.

“If they are planning to do something big in September or October, they’ll be laying the groundwork for it now,” a person close to Biden said.

When it comes to a disinformation operation, “the short term impact is the greatest,” the person said, pointing to the risk of an 11th hour maneuver that leaves fact-checkers scrambling.

Already, the effort does appear to be escalating: In his June 22 press conference, his second on Biden this year, Derkach accused Biden and one of his former advisers, Amos Hochstein, of “snatching” $1.5 billion, presenting no evidence for the claim.

The press conference included edited, recorded conversations of what sounded like then-VP Biden speaking to Poroshenko about Ukrainian energy company Naftogaz in December 2016. Biden was effectively in charge of Ukraine policy for the Obama administration, making these conversations part of his normal duties. But it’s still not clear how Derkach obtained the tapes, which he released more of on July 9.

The Foreign Intelligence Service of Ukraine has since issued a statement warning that “Russian special services continue to use their capabilities in Ukraine to conduct information operations against the Ukrainian state.” One prominent Ukrainian outlet suggested the warning was linked to Derkach’s press conferences.

Two days after the June 22 press conference, a Senate committee led by Ron Johnson (R-Wisc.) demanded transcribed interviews and documents from former Obama administration officials—including Hochstein, who has been one of Derkach’s main targets, and Blinken, now a senior foreign policy adviser to Biden’s campaign—as part of a Republican-led probe into Biden and his son.

The committee’s interviews with Hochstein and Blinken have not yet been scheduled, and the committee will seek to compel their testimony through a subpoena if need be, according to people familiar with the matter.

Among the subjects Johnson wants to discuss: a memorandum of understanding signed in 2014 between Burisma—the Ukrainian gas company whose board included Hunter Biden—and USAID, which does not mention either Joe Biden or his son.

Democratic leaders on Monday asked the FBI for an urgent briefing arising out of concern that members of Congress are being targeted by a foreign operation intended to influence the 2020 presidential election—among their concerns is that the Johnson probe has become a vehicle for “laundering” a foreign operation to damage Biden.

“We are gravely concerned, in particular, that Congress appears to be the target of a concerted foreign interference campaign, which seeks to launder and amplify disinformation in order to influence congressional activity, public debate, and the presidential election in November,” they said.

Betsy Woodruff Swan contributed reporting.