Sen. John McCain of Arizona called President Donald Trump's press conference with Russian President Vladimir Putin on Monday "one of the most disgraceful performances by an American president in memory."

Trump refused to acknowledge US intelligence agencies' consensus that Russia interfered in the 2016 election.

Several other Republicans also broke with Trump in denouncing his remarks.

Sen. John McCain of Arizona on Monday joined a chorus of Republican leaders in slamming President Donald Trump for his joint press conference with President Vladimir Putin in which Trump refused to acknowledge Russia's interference in the 2016 US election and attacked the FBI.

"Today's press conference in Helsinki was one of the most disgraceful performances by an American president in memory," McCain wrote in a blistering statement.

In his remarks, Trump said he didn't "see any reason" to believe the US intelligence agencies' conclusions that Russia meddled in the election, did not hold Russia accountable for its alleged transgressions, called the special counsel's Russia investigation "a disaster for our country," and bragged about his election win.

He finished by chastising the FBI, saying it did not take possession of the hacked Democratic National Committee server, as well as the FBI agent Peter Strzok.

McCain, who is battling an aggressive form of brain cancer, has publicly clashed with Trump on many occasions. Trump repeatedly insulted him during the 2016 campaign, notably once saying McCain, a Vietnam veteran, wasn't a true war hero because he had been captured as a prisoner of war.

McCain's daughter Meghan responded to Trump's press conference earlier Monday.

"I don't have anything quippy to tweet," she tweeted. "I'm horrified — and have never been more proud of the fact that Putin hates my father so much he personally sanctioned him on Russia's enemies list."

Read McCain's full statement below:

"Today's press conference in Helsinki 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. "President Trump proved not only unable, but unwilling to stand up to Putin. 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. "It is tempting to describe the press conference as a pathetic rout — as an illustration of the perils of under-preparation and inexperience. But these were not the errant tweets of a novice politician. These were the deliberate choices of a president who seems determined to realize his delusions of a warm relationship with Putin's regime without any regard for the true nature of his rule, his violent disregard for the sovereignty of his neighbors, his complicity in the slaughter of the Syrian people, his violation of international treaties, and his assault on democratic institutions throughout the world. "Coming close on the heels of President Trump's bombastic and erratic conduct towards our closest friends and allies in Brussels and Britain, today's press conference marks a recent low point in the history of the American Presidency. That the president was attended in Helsinki by a team of competent and patriotic advisors makes his blunders and capitulations all the more painful and inexplicable. "No prior president has ever abased himself more abjectly before a tyrant. Not only did President Trump fail to speak the truth about an adversary; but speaking for America to the world, our president failed to defend all that makes us who we are — a republic of free people dedicated to the cause of liberty at home and abroad. American presidents must be the champions of that cause if it is to succeed. Americans are waiting and hoping for President Trump to embrace that sacred responsibility. One can only hope they are not waiting totally in vain."

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