The potential case against Donald Trump for obstruction of justice continues to get stronger. On Monday night, The Washington Post reported that Trump separately asked Dan Coats, the director of national intelligence, and Mike Rogers, the director of the National Security Agency, to publicly deny that there was any evidence of collusion between his presidential campaign and the Kremlin. The effort to undermine the ongoing probe into Russian election interference came just days after James Comey confirmed that the F.B.I. was investigating communications and financial ties between Russia and several of Trump’s associates.

Both Coats and Rogers refused to comply with Trump’s request, which they deemed inappropriate, according to two current and two former officials with knowledge of the situation who spoke with the Post. An N.S.A. official documented Roger’s conversation with Trump in an internal agency memo, but it is unclear whether Coats’s interaction with the president was similarly recorded. NBC News confirmed the existence of the memo, citing an N.S.A. official who also said that Coats and Rogers discussed their respective interactions with Trump.

The president’s alleged efforts to pressure the two intelligence chiefs is the latest in a series of reports suggesting that Trump repeatedly acted to undermine or obstruct ongoing investigations into his campaign and associates. Last week, The New York Times reported that Trump explicitly asked Comey, then the director of the F.B.I., to shutter his agency’s investigation into Mike Flynn, the former national security adviser who resigned amid scandal in February. “I hope you can see your way clear to letting this go, to letting Flynn go,” the president said, according to a memo that Comey prepared after the meeting, part of which was read to the Times. “He is a good guy. I hope you can let this go.” Trump abruptly fired Comey weeks later. When asked why, both the president and the White House cited the F.B.I. probe.

It is unclear whether Trump approached Coats and Rogers in the same way that he did Comey. According to the Post’s account, Trump’s intention was to “muddy the waters” in regards to the F.B.I. investigation at a time when Democratic lawmakers were intensifying their rhetoric. “The problem wasn’t so much asking them to issue statements, it was asking them to issue false statements about an ongoing investigation,” a former senior intelligence official told the Post of Trump’s request to Coats.

One official who spoke with NBC News, however, painted Trump’s appeals to Coats and Rogers as less insidious and more indicative of the president’s ignorance about how the intelligence community works and the independence of the respective agencies and their heads. “I don't think [Trump] ever asked somebody to say something that they didn't believe was true,” the former official said.

He added that Coats and Rogers were “sufficiently concerned that it was an extraordinary thing that they took care to write it down, but not sufficiently concerned that they reported it.”

The White House pushed back on the reports in a statement. “The White House does not confirm or deny unsubstantiated claims based on illegal leaks from anonymous individuals,” a White House spokesman said.

The last part of that defense is not unfounded. For now, the reports detailing Trump’s interactions with Comey, Coats, and Rogers are all based on anonymous sources. But the White House may not be able to hide behind “anonymous individuals” for long. Former F.B.I. Director Robert Mueller, who Deputy Attorney General Rod Rosenstein appointed last week to serve as special counselor in the Trump-Russia probe, has reportedly already read Comey's memos detailing his interactions with Trump and will also have access to any documents detailing Coats's conversation with the president, too. Both Coats and Rogers declined to comment publicly on the recent reports when they appeared before Congress on Tuesday, for matters unrelated to the Russia probe. Comey was scheduled to testify before Congress on Wednesday, although his appearance has been postponed.

This post has been updated.