WASHINGTON - Ending a lengthy guessing game that he started with a cryptic tweet and that ensnared his administration in yet more controversy, US President Donald Trump on Thursday declared he never made and doesn't have recordings of his private conversations with ousted former FBI director James Comey.

"With all of the recently reported electronic surveillance, intercepts, unmasking and illegal leaking of information," Trump tweeted he has "no idea" whether there are "tapes" or recordings of the two men's conversations. But he proclaimed "I did not make, and do not have, any such recordings".

That left open the possibility recordings were made without his knowledge or by someone else. But he largely appeared to close the saga just days after he fired Comey, then the head of an investigation into Trump associates' ties to Russian officials.