​Washington: Senior Republican John McCain has called on US President Donald Trump to either prove his claim that former president Barack Obama tapped the phones at Trump Tower during last year's election campaign or to retract the accusation.

"The president has one of two choices, either retract or provide the information that the American people deserve," Mr McCain, chair of the Senate Armed Services Committee, said in an interview on CNN's State of the Union on Sunday.

"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."

Mr McCain is one of several top lawmakers in Congress calling on Mr Trump to provide evidence of his unsubstantiated claim that Mr Obama ordered Mr Trump's communications to be monitored.