President Trump is wrestling with challenges both at home and abroad -- but on Twitter he's wrestling with CNN.

On Sunday morning the president's personal Twitter account, which has 33 million followers, posted a 28-second video of a WWE broadcast. The video was edited to show Trump beating up a man with a CNN logo on his face.

A short time later, the official @POTUS account retweeted Trump's tweet to its 19 million followers. It is one of the president's most-shared, most-retweeted posts ever.

Sunday marked another escalation in Trump's ongoing war against the news media -- and against CNN in particular.

Trump, a frequent CNN viewer, regularly lashes out at the network's coverage.

Some of his fans laughed at the video. Others rolled their eyes. But it was taken seriously by members of the media, some of whom have faced threats for their reporting.

Some Twitter users flagged the tweet and reported it to the social networking company, saying it violated the company's terms of service prohibiting "hateful conduct." But Twitter said it determined that the tweet is not a violation.

In a statement, CNN called it a "sad day when the President of the United States encourages violence against reporters."

The statement brought up the fact that Trump's deputy press secretary Sarah Huckabee Sanders said just a few days ago that "the president in no way form or fashion has ever promoted or encouraged violence. If anything, quite the contrary."

"Clearly" Sanders "lied," the CNN statement said.

"Instead of preparing for his overseas trip, his first meeting with Vladimir Putin, ‎dealing with North Korea and working on his health care bill, he is involved in juvenile behavior far below the dignity of his office," the statement added. "We will keep doing our jobs. He should start doing his."

Several journalism advocacy groups also weighed in.

"We condemn the president's threat of physical violence against journalists," the Reporters Committee for Freedom of the Press said. "This tweet is beneath the office of the presidency. Sadly, it is not beneath this president."

And Dean Baquet, the executive editor of The New York Times, said "I think it is unseemly that the president would attack journalists for doing their jobs, and encourage such anger at the media."

Before becoming president, Trump sometimes appeared at WWE matches and occasionally joined in the fighting. So it was relatively easy for someone to tweak the old video and superimpose the CNN logo onto the other fighter's face.

Who created the anti-CNN video? There was no immediate answer, but a version of the video appeared on a pro-Trump Reddit thread several days ago.

Some commentators, especially those inclined to support Trump, laughed at the video and savored the president's latest media critique.

Others derided the video as juvenile and unbecoming of the U.S. president.

Infographic: Trump tweets and the TV news stories behind them

"It's not just anti-CNN. It's anti-freedom of the press," CNN political analyst Carl Bernstein said on "Reliable Sources" on Sunday. "It's very disturbing. There's nothing lighthearted about it whatsoever."

CNN, The New York Times, The Washington Post have been some of the president's recent targets.

On Saturday Trump tweeted that he wants to rebrand "Fake News CNN" as "Fraud News CNN."

Sunday's video reiterated that message with a Photoshopped "FNN" logo.

Several prominent Democrats, including House minority leader Nancy Pelosi, condemned the video.

"Violence & violent imagery to bully the press must be rejected," Pelosi wrote. "This #July4th, celebrate freedom of the press, guardians to our democracy."

Violence & violent imagery to bully the press must be rejected. This #July4th, celebrate freedom of the press, guardians to our democracy — Nancy Pelosi (@NancyPelosi) July 2, 2017

Congressman Adam Schiff‏ pointed out that a journalist in Montana was recently body-slammed by Greg Gianforte, a Republican businessman running for office at the time. (Gianforte won the election, and he is now in the House of Representatives.)

Putting the focus on Trump, Schiff asked, "Where will his downward spiral take us?"

Mike Coffman, a Republican member of the House from Colorado, replied on Twitter: "Exactly what I meant when I said, #StopTheTwitterTantrums"

On ABC's "This Week," anchor Martha Raddatz asked Homeland Security Adviser Thomas Bossert to react to the video.

"No one would perceive that as a threat. I hope they don't," he said.

Ana Navarro disagreed. She called Trump's tweet "an incitement to violence. He is going to get someone killed in the media." Navarro, a Republican who is fiercely critical of the president, is a commentator on both CNN and ABC.

Some other Republicans suggested that there was an overreaction to the video.

Ben Ferguson, a conservative talk show host and CNN commentator, said he thought Trump's WWE tweet was one of the more "humorous moments" of the president's never-ending feud with the media.

"I don't think it incites violence," Ferguson said on "Reliable Sources." "He's trying to make it abundantly clear that there are people in the media who have made it their personal mission and their job to destroy this president."

Other guests on "Reliable Sources" said Trump should differentiate between reporters who are trying to find out facts and commentators who sometimes express extremely harsh opinions about the president.

Bernstein noted that Trump himself has embraced news coverage from CNN and other outlets when it benefits him personally.

"When it suits him, it's great news. When it doesn't, it's 'fake news,'" Bernstein said. "And the nexus of fake news in America is the Trump White House."