Sen. Lindsey Graham (R-S.C.) on Sunday called for the White House to turn over any recordings, if they exist, taped during a meeting between President Donald Trump and former FBI Director James Comey.

Graham, who appeared on NBC’s “Meet the Press,” was commenting on a recent tweet by the president that alludes to secret recordings made during a private dinner he had with Comey. Trump appeared to threaten to release them if the former director spoke to the press about his recent firing, an allegation Graham called “inappropriate.”

“You can’t be cute about tapes,” the senator told host Chuck Todd. “If there are any tapes of this conversation they need to be turned over. I doubt if there are, but we need to clear the air.”

Graham, who’s said he’s on such good terms with the president that he gets calls even when he’s asleep, also had a word of advice for Trump: Stop tweeting about these things.

“This tweet has to be answered,” he said. “I would advise the president not to tweet or comment about the investigation as we go forward. The president needs to back off here.”

Lawmakers have been grappling with how to handle the supposed tapes since Trump tweeted about them last week. Officials aren’t actually sure whether they exist, but an aide to the Senate Intelligence Committee told HuffPost the group was exploring ways to obtain them in case they do.

“There’s no simple mechanism, but you can be sure we’ll take a look at it,” the aide said.

White House press secretary Sean Spicer wouldn’t deny the tapes existed when asked about them last week by several reporters, and only said he had “nothing further to add” about the potential recordings.

Sen. Chuck Schumer (D-N.Y.) has also demanded that Trump turn over the tapes to Congress, and warned the president that destroying them “would be a violation of law.”

“He should turn them over to Congress and to the investigators,” Schumer said on CNN. “If there are no tapes, he should apologize to both Jim Comey and the American people for misleading them.”