Sen. John McCain, R-Ariz., on Friday told the Munich Security Conference that President Trump’s administration is in “disarray” and has “a lot of work to do.”

McCain has emerged as one of Trump’s most vocal critics from his own party. Most recently, there has been a public fued between the administration and McCain over the Yemen raid that resulted in the deaths of civilians and the loss of a Navy SEAL.

McCain, who did not call out Trump by name, pointed to the resignation of Trump’s former national security adviser to illustrate his point.

"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,” McCain said, according to Reuters. “The president, I think, makes statements (and) on other occasions contradicts himself. So we’ve learned to watch what the president does as opposed to what he says.”

McCain pointed to the “profound concern across Europe” that the U.S. is laying down its “mantle of global leadership.”

“I can only speak for myself, but I do not believe that that is the message you will hear from all of the American leaders who cared enough to travel here to Munich this weekend,” he said.

Vice President Pence gave a speech Saturday morning where he assured NATO that the U.S. "will be unwavering in our commitment to this trans-Atlantic alliance."

The Washington Post ran a headline, in an analysis article, “John McCain just systematically dismantled Donald Trump’s entire worldview.” The paper reported that “it was a striking display from a senior leader of a party when it comes to a president of the same party.

McCain’s comments came days after Defense Secretary Jim Mattis told fellow NATO members to increase military spending by year's end or risk seeing the U.S. curtail its defense support — a stark threat given Europe's deep unease already over U.S.-Russian relations.

Echoing Trump's demands for NATO countries to assume greater self-defense responsibility, Mattis said Washington will "moderate its commitment" to the alliance if countries fail to fall in line.

The Associated Press contributed to this report