The White House Thursday invited the top Democrat on the House intelligence committee and the leaders of the Senate intelligence committee to view classified material previously seen by House committee chairman Rep. Devin Nunes, R-Calif.

In a letter to the House and Senate intelligence committee's chairman and ranking member, White House Counsel Don McGhan offered to "make these documents" available for Rep. Adam Schiff, D-Calif. to inspect. McGhan added that he believed the documents are "necessary to determine whether information collected on U.S. persons was mishandled and leaked," a reference to alleged surveillance of President Trump's campaign staff and transition team.

In a response, Schiff told McGhan, "I look forward to reviewing these materials at the earliest opportunity."

Sources told Fox News that Senate intelligence committee chairman Richard Burr, R-N.C., and ranking member Mark Warner, D-Va., had received the same invitation from McGhan. The committee responded to the White House by asking for the intelligence agencies "that own the intelligence documents in question to immediately provide them directly to the Committee."



The exchange of letters took place as Fox News confirmed that two White House staffers — Ezra Cohen-Watnick, a senior intelligence director at the National Security Council, and Michael Ellis of the White House Counsel’s office — aided Nunes in reviewing intelligence at the Eisenhower Executive Office Building on the White House grounds March 21. The staffers' identities were first reported by The New York Times.

Nunes told reporters last week that he had seen troubling information about the improper distribution of Trump associates' intercepted communications, and he briefed the president on the material before informing Schiff.

Speaking on Capitol Hill Thursday, Schiff said he was "more than willing" to accept the White House offer to view new information. But he raised concerns that Trump officials may have used Nunes to "launder information to our committee to avoid the true source."



"The White House has a lot of questions to answer," he declared.



Instead, the White House continued to sidestep queries about its role in showing Nunes classified information that appears to have included transcripts of foreign officials discussing Trump's transition to the presidency, according to current and former U.S. officials. Intelligence agencies routinely monitor the communications of foreign officials living in the U.S., though the identities of Americans swept up in that collection is to be protected.



Early last week, White House officials privately encouraged reporters to look into whether information about Trump associates had been improperly revealed in the intelligence gathering process. Days later, Nunes announced that he had evidence, via an unnamed source, showing that Trump and his aides' communications had been collected through legal means but then "widely disseminated" throughout government agencies. He said the collections were not related to the Russia investigation.



Trump spokesman Sean Spicer said Thursday the material the White House wants the House and Senate intelligence leaders to view was discovered by the National Security Council through the course of regular business. He would not say whether it was the same material Nunes had already seen.



A congressional aide said Schiff did not receive the White House letter until after Spicer announced it from the White House briefing room.



Spicer had previously dismissed the notion that the White House had funneled information to Nunes, saying the idea that the congressman would come and brief Trump on material the president's team already had "doesn't pass the smell test." The White House quickly embraced Nunes' revelations, saying they vindicated Trump's explosive and unverified claim that President Barack Obama wiretapped his New York skyscraper.



Nunes has said the information he received did not support that allegation, which has also been disputed by Obama and top intelligence officials.



Cohen-Watnick is among about a dozen White House officials who would have access to the types of classified information Nunes says he viewed, according to current and former U.S. officials. He's become a controversial figure in intelligence circles, but Trump decided to keep him on over the objections of the CIA and National Security Adviser H.R. McMaster, according to the officials. They spoke only on condition of anonymity because they were not authorized to comment publicly by name.



Cohen-Watnick and Rep. Nunes both served on the Trump transition team.



Nunes has repeatedly sidestepped questions about who provided him the intelligence reports, though he pointedly has not denied that he sources were in the White House. House Speaker Paul Ryan, R-Wis., in an interview with CBS' "This Morning" that aired Thursday, said Nunes told him a "whistleblower-type person" provided the information.

Nunes has declined to recuse himself from the investigation, despite repeated calls from Democrats to do so. Ryan has also expressed confidence in Nunes' conduct amid calls for Ryan to strip Nunes of his chairmanship.

Fox News' John Roberts and Chad Pergram contributed to this report. The Associated Press contributed to this report.