During an interview with President Donald Trump last week, Fox News host Bill O'Reilly called Russian President Vladimir Putin "a killer" — and Putin is not happy.

Putin's spokesman Dmitry Peskov told the Russian news agency TASS that O'Reilly should apologize for the statement.

"We believe that these words of Fox News correspondent are unacceptable [and] offensive," Peskov said. "We would prefer to receive an apology to the President of Russia from such a respected broadcaster."

However, Peskov avoided commenting on Trump's response to O'Reilly's comment.

During the interview on Fox News, Trump defended Putin, dismissing allegations that the Russian president is “a killer” by saying, “What do you think — our country’s so innocent?”

Trump, who in the past has praised Putin and argued that having a good relationship with the Russian president would be good for the US, seemed to dismiss allegations of Putin’s tight-fisted tactics.

“Do you respect Putin?” O’Reilly asked Trump.

“I do respect him but,” Trump replied.

“Do you? Why?” O’Reilly asked.

“Well, I respect a lot of people but that doesn’t mean I’m going to get along with him,” Trump responded. “He’s leader of his country. I say it’s better to get along with Russia than not. And if Russia helps us in the fight against ISIS, which is a major fight, and Islamic terrorism all over the world — that’s a good thing. Will I get along with him? I have no idea.”