Critics slammed former CBS News White House correspondent Mark Knoller on Saturday after he said President Biden's speech in Poland topped former President Ronald Reagan's "tear down that wall" speech. 

Biden's speech ended with him saying Russian Vladimir Putin "cannot remain in power." The White House appeared to walk back his comments shortly afterward, saying that Biden was calling for regime change.

BIDEN SAYS PUTIN ‘CANNOT REMAIN IN POWER' AS HE ASSURES UKRAINE: ‘WE STAND WITH YOU’ 

"The president’s point was that Putin cannot be allowed to exercise power over his neighbors or the region. He was not discussing Putin’s power in Russia, or regime change," a White House official told Fox News Digital. 

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President Joe Biden speaks about Ukraine in the East Room of the White House. (AP Photo/Alex Brandon)

"Tops Reagan’s 1987 "tear down this wall" speech," Knoller said on Twitter, prompting criticism from journalists and political commentators. 

WHITE HOUSE INSISTS TROOPS NOT GOING TO UKRAINE AFTER BIDEN COMMENTS IN POLAND

First lady Nancy Reagan and President Reagan walk on the White House south lawn in December 1986. (AP Photo/Dennis Cook, File)

Fox News contributor Mollie Hemingway said, "Oh Mark." Radio host Erick Erickson noted that no one walked back Reagan's comments. 

"Did the staff have to come out after Reagan’s speech and say JUST KIDDING GUYS HE DIDN’T MEAN THAT," Nick Searcy, an actor, said in response to Knoller's tweet. 

The Heritage Foundation's Nile Gardiner, a former aide to Margaret Thatcher, said, "Biden is no Reagan that's for sure."

"If topping means the exact opposite of what it actually means, absolutely," Fox News' Laura Ingraham said in response to Knoller's suggestion. 

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Biden visited Poland over the weekend and met with several Ukrainian refugees that have fled their country. Poland has accepted the majority of Ukrainian people fleeing Putin's war. 

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President Joe Biden boards Air Force One to fly to Warsaw, at Rzeszow-Jasionka Airport, in Jasionka, Poland, March 25, 2022. (Reuters/Evelyn Hockstein)

"Don't even think about moving on one single inch of NATO territory," he said during his speech. "We have a sacred obligation under Article Five to defend each and every inch of NATO territory with the full force of our collective power."

He stressed the importance of a united front and said that the U.S. and its allies must commit to be in the fight against Russia "for the long haul."

Biden also called Putin a "butcher" after meeting with displaced Ukrainian mothers and children in Warsaw. 

Fox News' Adam Shaw contributed to this report.