American media groups have urged the White House to condemn a parody video showing the US president massacring media outlets and political rivals.
The White House Correspondents' Association said it was "horrified" and urged Mr Trump to denounce the video.
It was on shown at an event organised by American Priority, a pro-Trump group. Organisers said the video had been part of a "meme exhibition".
President Trump's 2020 re-election campaign has disavowed it.
Campaign spokesman Tim Murtaugh told the BBC on Sunday: "That video was not produced by the campaign, and we do not condone violence."
On Monday, White House spokeswoman Stephanie Grisham wrote on Twitter that Mr Trump had "not yet seen the video".
"But based upon everything he has heard, he strongly condemns this video," she said.
However US media groups demanded that the president personally censure the video, which was played at a Trump resort in Miami, Florida, last week.
"All Americans should condemn this depiction of violence directed toward journalists and the President's political opponents," said Jonathan Karl, president of the White House Correspondents' Association. "We have previously told the President his rhetoric could incite violence."
A pro-Trump creator of viral video, MemeWorld, said the clip had been generated by one of its contributors, by TheGeekzTeam.
MemeWorld said in a statement that it did not condone violence.
"The Kingsman video is clearly satirical and the violence depicted is metaphoric," said its owner, who goes by the name Carpe Donktum. "No reasonable person would believe that this video was a call to action, or an endorsement of violence towards the media."
What is in the video?
Mr Trump's head is superimposed on the body of a man who goes on a killing rampage inside "the Church of Fake News".
The heads of the people he kills have been replaced with the logos of media organisations, including BBC News, CNN and the Washington Post, and political opponents such as Barack Obama and Hillary Clinton.
The video is a doctored version of scenes from 2014 movie Kingsman: The Secret Service, starring Colin Firth.
American Priority also sought to disassociate itself with the video, saying it was "not approved, seen, or sanctioned" by event organisers.
The video, the group added, was shown in a "side room" at the event and was only brought to the attention of organisers by the New York Times.
The president's son, Donald Trump Jr, and former White House press secretary Sarah Huckabee Sanders were scheduled to speak at the event, according to the New York Times.
"I wasn't aware of any video, nor do I support violence of any kind against anyone," Ms Sanders told the paper.
On Monday, Republican Party Chairwoman Ronna McDaniel took to Twitter to denounce the "horrific" video.
CNN said in a statement on Sunday: "Sadly, this is not the first time that supporters of the President have promoted violence against the media in a video they apparently find entertaining - but it is by far and away the worst.
During his 2016 campaign, and as president, Mr Trump has repeatedly lashed out at what the "fake news media", describing media outlets as "enemies of the people".
In recent weeks, Mr Trump ramped up his attacks on his political rivals and media organisations as an impeachment inquiry into his presidency escalated.
A similar parody video was shared on Mr Trump's Twitter page in 2017.
That clip was an altered version of Mr Trump's appearance at a WWE wrestling event in 2007, in which he "attacked" franchise owner Vince McMahon. In the video, a CNN logo appeared in place of Mr McMahon's head.