CNN anchor Brian Stelter and senior Trump campaign legal advisor Jenna Ellis traded barbs during a segment on Sunday where Mr Stelter predicted the president's advisers would one day look back with regret on their strategy to attack the integrity of traditional media outlets.
When Ms Ellis derided the "fake news media" as "peddlers of false information," Mr Stelter interrupted her with a plea to her future self not to use such terms.
"You understand that, like, some day you're going to regret this, right? Some day you're going to regret this, when your kids and your grandkids look back at this time, and you use slurs and smear us as fake news to hurt news outlets," Mr Stelter said, as he and Ms Ellis talked over one another.
"I think in 10 or 20 years if we just sit down and talk about this, you're going to realise how damaging it was. How damaging it was to use terms like 'fake news,' to attack journalists who are trying to do their jobs," Mr Stelter said.
Ms Ellis, who has worked for Mr Trump's reelection campaign since last November, shot right back at Mr Stelter, saying he and his colleagues are not journalists, but activists with poorly hidden motives.
This is specifically re: her constant use of the term "fake news" to disparage real news outlets and destroy trust https://t.co/Cre8xsIQ6L
— Brian Stelter (@brianstelter)
"You're not trying to do your job — you're not a journalist, Brian. You're an activist. That's the problem. You have an agenda, and your agenda is anti-Trump," Ms Ellis said.
"The American people see through that, and they are very grateful that this president is finally holding the fake news media accountable because you're activists. You're not reporting fact and truth," she said.
For years, Mr Trump and Republicans have co-opted the term "fake news" to describe news coverage they view as tinged with liberal bias, even if the stories they're denouncing have factual merit.
The 2016 presidential election saw a proliferation of fake news and disinformation, facilitated by social media, that many Democrats believe swung the election in Mr Trump's favour.
While US intelligence agencies have unanimously agreed Russia, led by President Vladimir Putin, ordered a sweeping disinformation campaign to interfere in the 2016 US election, they have said they cannot determine what effect, if any, the interference campaign had on the actual results.
The Republican-led Senate Intelligence Committee concluded in 2018 that Mr Putin wanted Mr Trump to win, though Mr Trump's allies are quick to point out that he was also the victim of many fake news stories that went viral online.
Most recently, Mr Trump chided "the Fake News" after people who watched him gingerly descend a ramp after delivering the commencement address at the US military academy at West Point questioned whether he was healthy.
"The ramp that I descended after my West Point Commencement speech was very long & steep, had no handrail and, most importantly, was very slippery," Mr Trump tweeted on Saturday.
"The last thing I was going to do is “fall” for the Fake News to have fun with. Final ten feet I ran down to level ground. Momentum!" the president wrote.