Republican Sen. John McCain believes the global order was more stable and established under President Obama than it is under President Trump.

McCain told The Guardian in a report that published Sunday that Trump's criticism of London Mayor Sadiq Khan following a terrorist attack in London earlier this month showed the United States no longer wants to be the world's leader.

"What do you think the message is? The message is that America doesn't want to lead," McCain said.

He said of the rest of the world: "They are not sure of American leadership, whether it be in Siberia or whether it be in Antarctica."

When he was asked if the U.S. had a better standing in the eyes of the world under Obama, McCain said, "As far as American leadership is concerned, yes."

It's a surprising comment from McCain, who has been a critic of the Trump administration but was a fervent opponent of Obama's foreign policy.

Trump's Twitter account is seemingly a stick in the craw of Republican lawmakers in the foreign policy realm.

Sen. Jeff Flake, R-Ariz., told The Guardian that Trump is inviting "serious consequences" with his tweets.

"I've said a number of times – it'd be easier if Trump wasn't tweeting so much," Flake said. "In terms of foreign policy, this is going to have serious consequences."