US Senator John McCain says lawmakers are not President Donald Trump's subordinates

Sen John McCain (R-AZ) as he leaves the Senate Chamber. (file photo)

US Senator John McCain has denounced President Donald Trump’s lack of experience, saying members of Congress will cooperate with the president whenever possible but they are “not his subordinates.”

"We must respect his authority and constitutional responsibilities," the Arizona Republican said during an international economic and policy conference in Lake Como, Italy.

"We must, where we can, cooperate with him. But we are not his subordinates. We don't answer to him. We answer to the American people,” he stressed.

McCain, a fierce critic of President Trump, emphasized the importance of Congress as a check on presidential power, adding, “We should value our identity as members of Congress more than our partisan affiliation.”

McCain, who is the chairman of the Senate Armed Services Committee, further said that Trump’s rhetoric and lack of experience have thrown the country’s relationships with foreign allies into doubt.

"I realize that I come to Italy at a time when many are questioning whether America is still committed to remaining engaged in the world, to upholding our traditional alliances, and standing up for the values we share," McCain said.

"I also realize — and there is no point in avoiding a little straight talk here — that this doubt has much to do with some of the actions and statements of our president."

US President Donald Trump boards Air Force One at Ellington Field on September 2, 2017. (Photo by AFP)

McCain said there is a “real debate” in the United States about the role it must play internationally and that the future of the world “will turn, to a large extent, on how this debate in America is resolved."

The remarks echoed a speech McCain made back in May in Australia, where he warned that Trump had “unsettled America's friends."

Trump has worried many traditional US allies by his controversial statements on foreign policy matters and US alliances with other countries. The president has also isolated the United States by pulling the country from the Paris Climate Accord.