"Well, that I can't talk about," Trump said Thursday in an interview with Fox News. "I won't talk about that. All I want is for Comey to be honest. And I hope he will be."
White House press secretary Sean Spicer also declined to answer a barrage of questions about Trump's tweet, saying "the President has nothing further to add on that."
The denials came hours after Trump issued a warning to the FBI Director he fired days earlier: "James Comey better hope that there are no 'tapes' of our conversations before he starts leaking to the press!"
If Trump did order a recording system installed in the Oval Office -- or elsewhere in the White House -- it would be the first of its kind since President Richard Nixon.
That's why Trump's tweet gave pundits and historians fresh ammunition to continue drawing comparisons between Trump and Nixon as they have in the days since Trump fired Comey, who as head of the FBI oversaw the investigation into potential coordination between Trump campaign associates and Russia during the 2016 election.
But it's the court cases and laws stemming from Nixon's secret recordings that could send Trump's tweet backfiring.
That's because Congress in 1974 passed the Presidential Recordings and Materials Preservation Act that designated tapes like those Nixon recorded as presidential records that must be preserved in federal archives.
"If Trump installed a taping system ... those are federal records thanks to Nixon's court challenges," said Timothy Naftali, a presidential historian and Nixon expert.
That means it's illegal to destroy presidential recordings and they could by subpoenaed by, say, Congress -- which is part of the reason why no president since Nixon has installed recording devices in the Oval Office.
"Most presidents after Nixon were skittish to do much taping," said presidential historian Douglas Brinkley.
It's unclear what Trump meant when he tweeted about "tapes" on Friday morning. But the public could soon find out as Reps. John Conyers and Elijah Cummings, both Democrats, on Friday requested copies of any such recordings from the White House counsel.
One source close to Trump said that while they didn't know whether Trump was recording White House conversations, they also wouldn't be surprised if he was.
"Yes, it sounds like something he would do," the source said, "for the purposes of protecting himself."
Phone call recordings would be less out of the ordinary, however.
Presidential calls with foreign leaders are sometimes recorded and logged by White House staff and the White House phone system has the capacity to record calls at the President's request.
"Anybody talking to Trump on the telephone has to think a recording is being made," said Brinkley. "But if you're meeting with Trump in a private dining room one on one you wouldn't think you're being recorded."
It was during a one-on-one dinner between Trump and Comey that Trump says he asked Comey if he could confirm he wasn't under investigation, which Comey did.
But it's also where sources close to Comey said Trump asked Comey to pledge his loyalty to him, which the FBI director refused to do, instead promising only "honesty."
The White House disputed that account.
One thing is clear: It would be much easier for Trump to record in-person conversations than it was in the Nixon era.
"Did he record or did somebody record? No idea," said John Dean, Nixon's former White House counsel. "But today it would be very easy. Today he could have a smart phone in his pocket and probably pick up a room conversation with some ease."