The US president's Helsinki summit with his Russian counterpart sparked criticism across the political spectrum, with Republican Senator John McCain calling it “one of the most disgraceful performances by an American president in memory".
But the meeting has also been attacked by a slew of hosts on the right-wing news channel – known for its unashamed Republican bias and vehemently pro-Trump rhetoric – with pundits rounding on the president for accepting the Russian leader’s denial the Kremlin meddled in the 2016 US presidential election.
Fox Business's Neil Cavuto labelled his refusal to challenge Mr Putin on Russian election meddling “disgusting” and said the president was “essentially letting the guy get away with this, not even offering a mild, a mild criticism".
He added: “That’s what made his performance disgusting. Only way I feel. Not a right or left thing to me. It is wrong.”
Trish Regan, also of Fox Business, branded the president's appearance "unpatriotic".
Ms Regan said she had wanted to suggest the media was wrong for questioning whether to have the summit, particularly after 12 Russian military intelligence agents were indicted by the FBI last week for interfering in the 2016 election, but she could not.
“He should have defended us,” she said on air.
She described the press conference as “horrible” on her show, saying: “From what I saw, I did not like that our president was not defending us and honouring his intelligence community."
Jack Keane, a Fox guest and retired four-star general, said Mr Trump’s performance was “stunning and disappointing".
While Shepard Smith, the Fox News anchor who has most often pushed back against the president, shined a light on ferocious criticism of the president.
"Shameful, disgraceful, treasonous - three of the descriptions of what President Trump did today in Helsinki," Mr Smith said, referring to comments by Mr McCain and former CIA Director John Brennan.
Stuart Varney, a Fox News host who routinely promotes Mr Trump’s policies, criticised the president for what was “not a very forceful presentation".
And two of the network's broadcasters piled in on the criticism, arguing Mr Putin had emerged ahead.
Business reporter Ashley Webster said: “He outmanoeuvred our president. I was very surprised. I thought Trump was going to push hard.”
Chief political anchor Bret Baier called the press conference “almost surreal at points".
Brit Hume, senior political analyst at Fox News, said Mr Trump's answer to a question on whether he believed the US intelligence assessment that Russian interfered in the 2016 election was "a vague and rambling nonanswer".
Mr Hume added: "Lame response, to say the least."
Trump, finally asked whom he believes on Russia interference, gives a vague and rambling non-answer, with renewed complaints about Hillary’s server. Says he trusts US intel but made clear he takes Putin’s denials seriously. Lame response, to say the least.— Brit Hume (@brithume) July 16, 2018
Guy Benson, a Fox News contributor, branded it "easily one of [Trump's] worst days as president".
Appalling moral equivalence & equivocation — rooted in an embarrassing, juvenile, insecure, consuming obsession over his own legitimacy. Easily one of his worst days as president. And again, juxtapose that performance with how he just treated our European & North American allies.— Guy Benson (@guypbenson) July 16, 2018
Mr Trump and Mr Putin held nearly two hours of one-on-one talks without their advisers in Helsinki on Monday.
At a news conference after the summit, Mr Trump was asked if he believed his own intelligence agencies or the Russian president when it came to allegations of interfering in the election.
But Mr Trump directly contradicted his own officials, saying Mr Putin had issued a “strong, impressive denial” and he saw "no reason" why Russia would have been involved.
The billionaire president also blamed poor relations with Russia on past US administrations rather than the actions of Russia.
Mr Trump later backtracked and sought to defend himself, tweeting he had "GREAT confidence in MY intelligence people". But he also made it clear he would continue to push for Washington and Moscow to "get along".
As I said today and many times before, “I have GREAT confidence in MY intelligence people.” However, I also recognize that in order to build a brighter future, we cannot exclusively focus on the past – as the world’s two largest nuclear powers, we must get along! #HELSINKI2018— Donald J. Trump (@realDonaldTrump) July 16, 2018
The criticism Fox News personalities levied at Mr Trump is the most substantial since the 2016 election.
The Rupert Murdoch-owned news channel’s opinion hosts have mostly backed the Trump administration, which has hired a number of people with links to Fox News.