The Russian government has demanded an apology from Fox News after anchor Bill O’Reilly called President Vladimir Putin “a killer” during an interview with U.S. President Donald Trump.

“We think such words a Fox News correspondent are unacceptable, insulting,” Kremlin spokesman Dimitri Peskov told reporters, according to Russia’s state-run RIA news agency.

“We would prefer to receive apologies to our president from such a respectable television company,” he added.

Fox News and Bill O’Reilly have yet to respond to Peskov’s comments, which came in the early hours of the morning in U.S. time zones.

O’Reilly’s comments came in an interview with Trump that was broadcast before the Super Bowl on Sunday.

The exchange that stoked the Kremlin’s ire saw O’Reilly ask Trump if he respects Putin. The president said, “Well, I respect a lot of people but that doesn’t mean I’m going to get along with him.”

O’Reilly then said, “Putin’s a killer,” and Trump responded: “There are a lot of killers. We’ve got a lot of killers. What, do you think our country’s so innocent?”

Russia’s upset at O’Reilly’s comments came after Republicans and Democrats alike expressed disquiet at Trump’s apparent assertion that the U.S. and Russia behaved in a comparable manner on the world stage.

“The Russians annexed Crimea, invaded Ukraine, and messed around in our elections,” Senate Majority Leader Mitch McConnell told CNN’s “State of the Union.”

“No, I don’t think there is any equivalency between the way the Russians conduct themselves and the way the United States does,” he added.

Trump’s comments forced Vice President Mike Pence on the defensive. Appearing on NBC’s “Meet The Press,” he denied that Trump was trying to draw a moral equivalency between Russia and the U.S.

Related: Trump’s Russia-U.S. Comparison Rejected by Democrats and Republicans.

“What you’re hearing there is a determination by the president of the United States to not let semantics or the arguments of the past get in the way of exploring the ability to work together with Russia and with President Putin in the days ahead,” Pence said.

While Russia was evidently willing to speak out against O’Reilly’s comments, it was more circumspect when it came to anything Trump had said about the Russian leader.

“As for statements by the U.S. president, I would prefer not to comment in this case,” Peskov said.