Sen. John McCain (R) issued a blistering statement condemning President Trump’s Monday summit and subsequent press conference with Russian President Vladimir Putin, which the Arizona senator said was “one of the most disgraceful performances by an American president in memory.”

“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 said. He said that Trump was speaking from the “the same script” as Putin when he “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.”

McCain, who for months has been undergoing cancer treatments in Arizona, brought up Trump’s “bombastic and erratic conduct towards our closest friends and allies in Brussels and Britain,” while calling Monday’s press conference “a recent low point in the history of the American Presidency. ”

“No prior president has ever abased himself more abjectly before a tyrant,” McCain said.

Read the full statement below: