Republican Sen. John McCain on Friday broke with the reassurances that U.S. officials have sought to convey on their debut trip to Europe, saying the administration of President Donald Trump is in "disarray."

McCain, a Trump critic, told the Munich Security Conference that the resignation of the president's security adviser, Michael Flynn, over his contacts with Russia reflected deep problems in Washington.

"I think that the Flynn issue obviously is something that shows that in many respects this administration is in disarray and they've got a lot of work to do," said McCain, even as he praised Trump's defense secretary.