US President Donald Trump tweeted an apparent warning to sacked FBI chief James Comey on Friday not to "leak" details of their conversations to the media, and hinted the interactions may have been recorded.

‍Trump on Tuesday ‍fired Comey, the man who led the agency charged with investigating his campaign's ties with Russia -- a move that sent shockwaves through Washington.

"James Comey better hope that there are no 'tapes' of our conversations before he starts leaking to the press!" Trump wrote in one of a series of tweets criticizing the media's response to Comey's ousting.

The tweets came after a report by The New York Times on Thursday claimed Trump had demanded a pledge of loyalty from Comey at a dinner in January. 

Comey declined, instead offering to be “honest,” a person close to the former director said, according to the report. When Trump then pressed for “honest loyalty,” Comey told him, “You will have that,” the associate added.

White House spokeswoman Sarah Huckabee Sanders disputed that report and said the president would “never even suggest the expectation of personal loyalty.” Officials did not immediately respond to questions about whether Trump recorded his discussions with the FBI director.

In an interview Thursday with NBC News, Trump said Comey had told him prior to being sacked that he was not under investigation over alleged Russian involvement in the US elections. “I said, ‘If it’s possible, would you let me know, am I under investigation?’ He said you are not under investigation.” 

The president’s Twitter comments on Friday again raised the specter of Richard Nixon, whose secretly taped conversations and telephone calls in the White House ultimately led to his downfall in the Watergate scandal. Trump’s firing of Comey already has left him with the dubious distinction of being the first president since Nixon to fire a law enforcement official overseeing an investigation tied to the White House.

Trump was widely known to record some phone conversations at his office in Trump Tower during his business career, sometimes remarking to aides after a call as to whether or not he had taped that one.

Associates of the former FBI director, who remained out of sight Friday at his suburban Virginia home, said they believed any recording would validate Comey’s side of the story.‍

Trump, in his NBC interview, said he had been intending to fire Comey for months and that it had nothing to do with the Russia investigation.

But he also said, “In fact when I decided to just do it, I said to myself, I said you know, this Russia thing with Trump and Russia is a made-up story, it’s an excuse by the Democrats for having lost an election that they should have won.”

Even before Trump’s provocative tweets, the White House was scrambling to clarify why Comey was fired.

The White House initially cited a Justice Department memo criticizing Comey’s handling of last year’s investigation into Democratic candidate Hillary Clinton’s emails as the impetus.

(Source: AP, CGTN)