Washington (CNN) Sen. John McCain released a powerful statement Monday criticizing President Donald Trump, calling his news conference with Russian President Vladimir Putin "one of the most disgraceful performances by an American president in memory."

The Republican senator from Arizona also called the press conference in Helsinki a "recent low point" in the history of the presidency and called the summit "a tragic mistake".

"Today's press conference in Helsinki was one of the most disgraceful performances by an American president in memory," McCain said. "The damage inflicted by President Trump's naiveté, egotism, false equivalence, and sympathy for autocrats is difficult to calculate. But it is clear that the summit in Helsinki was a tragic mistake."

McCain's statement also refers to Trump's sidestepping of a reporter's question who asked who Trump believed on whether Russia meddled in the 2016 presidential election.

"President Trump proved not only unable, but unwilling to stand up to Putin," McCain said. "He and Putin seemed to be speaking from the same script as the president made a conscious choice to defend a tyrant against the fair questions of a free press, and to grant Putin an uncontested platform to spew propaganda and lies to the world."

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