FILE PHOTO: U.S. President Donald Trump disembarks from Air Force One at Los Angeles International Airport in Los Angeles, California on September 17, 2019. REUTERS/Tom Brenner

WASHINGTON (Reuters) - President Donald Trump’s promise to a foreign leader so troubled an official in the U.S. intelligence community that it prompted them to file a whistleblower complaint, the Washington Post reported on Wednesday.

The Post, which cited two former officials familiar with the matter, said it was not immediately clear which foreign leader Trump was speaking with or what he pledged to deliver. The communication was a phone call, one former official said, according to the Post.

Intelligence Community Inspector General Michael Atkinson determined that the complaint was credible and troubling enough to be considered a matter of “urgent concern,” a legal threshold that requires notification of congressional oversight committees, the Post said.

But the acting Director of National Intelligence Joseph Maguire has refused to share details about the complaint with lawmakers, the Post reported.

Maguire has defended his refusal by asserting that the subject of the complaint is beyond his jurisdiction, the Post said.

House of Representatives Intelligence Committee Chairman Adam Schiff, a Democrat, has sought to compel U.S. intelligence officials to disclose the full details of the whistleblower complaint to Congress.

Atkinson is scheduled to appear at a closed hearing of the committee on Thursday and Maguire has agreed to testify before the panel in open session a week later, Schiff said in a statement.

The White House did not immediately respond to requests for comment. Representatives of the Office of the Director of National Intelligence could not be reached.