"With all of the recently reported electronic surveillance, intercepts, unmasking and illegal leaking of information, I have no idea whether there are 'tapes' or recordings of my conversations with James Comey," Trump said on Twitter. "But I did not make, and do not have, any such recordings."
The admission follows Trump's apparent threat to Comey after Trump fired him that the former head of the FBI "better hope that there are no 'tapes' of our conversations".
In a three-hour take-down of Trump's integrity, Comey told a Senate panel he hoped Trump recorded their private conversations, calling on him to release any tapes.
Trump has publicly disputed many of the charges Comey made during his testimony, including that Trump sought a pledge of loyalty, and asked Comey to drop an investigation into a former top official.
A House committee also investigating the Trump campaign's possible collusion with Russia had set a Friday deadline for the White House to hand over any tapes if they exist.