Senate Armed Services Committee Chairman John McCain (R-Ariz.) called Sunday for President Trump to either prove his claim that President Barack Obama tapped the phones in Trump Tower during last year’s election campaign or drop the accusation.

“The president has one of two choices, either retract or provide the information that the American people deserve,” McCain said in an interview on CNN’s “State of the Union.” “I have no reason to believe that the charge is true, but I also believe that the president of the United States could clear this up in a minute.”

Sens. Lindsey O. Graham (R-S.C.) and Sheldon Whitehouse (D-R.I.) also formally requested the information last week in a letter to FBI Director James B. Comey and acting deputy attorney general Dana Boente. Trump administration officials have not provided any evidence to back up the president’s claim from earlier this month.

“If the allegation is left out there, it undermines the confidence the American people have in the entire way that the government does business,” McCain said.