A whistleblower's report that was submitted to the inspector general for the intelligence community centers on an interaction between President Trump and a foreign leader, the Washington Post reported Wednesday, citing two former U.S. officials.

The identity of the whistleblower and details of the claim remain unknown – but the Post reported that the interaction between Mr. Trump and the foreign leader involved a "promise."

The Post said an intelligence official found it "so troubling" that he or she was prompted to file a whistleblower complaint on August 12 with the inspector general, Michael Atkinson.

Atkinson concluded that the complaint was credible enough to be considered an "urgent concern." Atkinson will testify on Capitol Hill Thursday in a closed-door hearing.

Mr. Trump denied that he said anything inappropriate to a foreign leader, writing on Twitter Thursday that the Post report was "Fake News."

"Another Fake News story out there - It never ends! Virtually anytime I speak on the phone to a foreign leader, I understand that there may be many people listening from various U.S. agencies, not to mention those from the other country itself. No problem!" Mr. Trump wrote.

Another Fake News story out there - It never ends! Virtually anytime I speak on the phone to a foreign leader, I understand that there may be many people listening from various U.S. agencies, not to mention those from the other country itself. No problem! — Donald J. Trump (@realDonaldTrump) September 19, 2019

"Knowing all of this, is anybody dumb enough to believe that I would say something inappropriate with a foreign leader while on such a potentially "heavily populated" call. I would only do what is right anyway, and only do good for the USA!" Mr. Trump continued in a second tweet.

The report has caused a rift between Congress and the intelligence community. House Intelligence Committee Chairman Adam Schiff issued a subpoena to obtain the whistleblower's complaint – but Acting Director of National Intelligence Joseph Maguire is refusing to hand it over.

Maguire said he determined the allegations did not merit "urgent concern," and since they relate to a person outside the intelligence community, he is not required to pass them along to Capitol Hill.

Schiff pointed out that this is the first time a Director of National Intelligence has overruled a determination from the inspector general, and raised concerns that the refusal may be a sign of a cover-up to protect the president.

Speaking to reporters on Thursday after the inspector general appeared before the committee, Schiff said that his committee still does not have access to the report. He said that it was unclear whether "the White House is directly involved" in keeping the report private.

"We do know that they are making some claim that a privilege may apply," Schiff said about the White House. "There are other institutions involved that are preventing us from getting the complaint."

Schiff said Sunday on "Face the Nation" that it's fair to assume the report involves "the president, or people around him, or both."

