John McCain has released a blistering rebuke to Donald Trump's controversial statements about his Nato allies, thanking them for their "patience" and slamming the president for his insults.

The Arizona Republican senator and chairman of the Senate Committee on Armed Services condemned Mr Trump for claiming allies like Germany were "delinquent" in the amount they pay towards the Alliance compared to the US.

"President Trump’s performance at the Nato summit in Brussels was disappointing, yet ultimately unsurprising," he said in a statement. “There is little use in parsing the president’s misstatements and bluster, except to say that they are the words of one man. Americans, and their Congress, still believe in the transatlantic alliance and the North Atlantic Treaty Organisation, and it is clear that our allies still believe in us as well."

Mr Trump began his trip to Europe by meeting with Nato members on Wednesday morning, in which he criticised his nation's allies for not paying into the alliance as much as the US. His comments sparked an impromptu debate with Nato Secretary General Jens Stoltenberg, who said "In the history of Nato we have had many disagreements and we have been able to overcome them again and again."

Mr Trump went on to claim Germany was "totally controlled by" Russia, citing a trade deal between both nations which he said was "very inappropriate."

"It certainly doesn't seem to make sense that they paid billions of dollars to Russia and we have to defend them against Russia," he said. "How can you be together when a country is getting its energy from the person you want protection against or from the group that you want protection against?"

The comments sparked backlash from elected officials on both sides of the political aisle, as well as German Chancellor Angela Merkel, who defended her country and its contributions to the global alliance.

Mr McCain also defended the US allies on Thursday, saying “that President Trump signed the Brussels Summit Declaration and ultimately expressed confidence in the future of the alliance is testament to the patience, forbearance, and commitment of our steadfast Nato partners."

“Now all eyes turn to Helsinki, where President Trump is set to meet with Vladimir Putin," he continued. "The president's task is to reverse his disturbing tendency to show America's adversaries the deference and esteem that should be reserved for our closest allies. He must show that he can be strong and tough with Vladimir Putin — not for its own sake, but to demonstrate his willingness to defend America, its allies, our shared interests, and our common values against those who threaten them."

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