Sen. Chuck Grassley (R-Iowa) said on Monday that he was lifting his two-year hold on President Trump's pick to be the top U.S. counterintelligence official.

Grassley pointed to documents he had received from Attorney General William Barr and acting Director of National Intelligence Richard Grenell as a key factor in his decision to end his opposition to William Evanina's nomination to be director of the National Counterintelligence and Security Center.

"Due to the recent actions by the Office of the Director of National Intelligence (ODNI) and the Attorney General to finally respond to my very longstanding oversight requests, I withdraw my objection to Mr. Evanina’s nomination," Grassley said in a statement.

"Thanks to their commitment to transparency, I have received access to the types of documents that I asked for almost two years ago in June 2018," he added. "If their predecessors had simply respected legitimate congressional oversight and their agreements with me and the Judiciary Committee from the beginning, Mr. Evanina would have been confirmed long ago."

Grassley announced in June 2018 that he would put a hold on Evanina's nomination because the intelligence community had not responded to congressional inquiries in a timely matter. He placed a second subsequent hold in March 2019.

"Let this also be a reminder that when it comes to congressional oversight, I will use all the tools at my disposal to get to the truth of the matter and get access to the records that I believe are necessary to advance my investigations," Grassley said on Monday.

Trump nominated Evanina in February 2018. Evanina has been filling the position since 2014, but lawmakers subsequently decided the post should require Senate confirmation.

Grassley’s hold didn't formally block the Senate from voting on Evanina, but his actions would have required Senate Majority Leader Mitch McConnell (R-Ky.) to file cloture and use up valuable floor time for days to get the nominee confirmed. That path also would have forced McConnell to go against a chairman from his own party.

Grassley, who is head of the Finance Committee, has said his decision to effectively stall Evanina's nomination was never personal.

"I did not question Mr. Evanina’s credentials in any way, and I put my statement of those reasons in the Record. I have done that consistently, not only since the rules of the Senate first required every Member to do that but even before that rule was put in place," Grassley reiterated on Monday.

But he also previously referenced text messages between Peter Strzok and Lisa Page — two FBI officials whose text messages critical of Trump caused a scandal — for part of the reason for his decision to hold up the nomination.

“In some of the text messages, an individual named ‘Evanina’ is mentioned in the context of government officials having briefed then Vice President-elect Pence on national security related issues and planning to brief him a second time,” Grassley said.

He added that the Senate Judiciary Committee “needs to more fully understand the meaning of the apparent references to Mr. Evanina in the Strzok-Page texts and will need to obtain further context from him and the Justice Department.”