“It’s challenging to gather this intelligence and this data,” Psaki said during the daily press briefing. “While there is low-to-moderate assessment in these reports, we felt it was important for our intelligence community to look into it.”

The Kremlin has steadfastly denied the allegations that it proffered bounties though its military intelligence service, the GRU. However, Psaki said the intelligence community has higher confidence in other reports of the GRU’s involvement in the region.

“This information really puts the burden on Russian and the Russian government to explain their engagement here,” she said. “We still feel there are questions to be answered by the Russian government.”

The administration’s admission undercuts a narrative wielded by then-candidate Joe Biden against former President Donald Trump on the campaign trail. Biden repeatedly raised the possibility of Russian bounties as further evidence that Trump treated Russia with kid gloves at the expense of the military, and used it as a cudgel against him.

At the time, Trump had dismissed initial media reporting of the allegations as a “hoax” and a "fake issue" and later said that intelligence officials had not briefed him on the alleged bounties because they did not believe it to be credible information.

Biden had raised the bounty issue, among other topics, with Russian President Vladimir Putin in January when the two leaders held their first call together after Biden took office. The president did not bring it up during a subsequent call with Putin earlier this week, according to a summary put out by the White House.

On Thursday, Biden levied new sanctions on Putin's government and expelled 10 Russian diplomats from the United States in response to election interference, cyberespionage and other hostile actions. Some lawmakers have urged Biden to go even further, including targeting the Nord Stream 2 pipeline between Russia and Germany — a move that would be complicated by Germany being one of the U.S.'s key allies.

“This is the start of a new U.S. campaign against Russian malign behavior,” Treasury Secretary Janet Yellen said in a statement.