The Kremlin said on Wednesday that it was not sure of the veracity of a CNN article that reported US President Donald Trump had once threatened to bomb Moscow to deter Russian President Vladimir Putin from attacking Ukraine.

CNN’s report, opens new tab cited audio recordings of Trump telling a private gathering of donors amid his pre-election campaign in 2024 that he had once warned Putin that he would "bomb the sh*t out of Moscow" if Russia attacked Ukraine.

Asked about the report, Kremlin spokesman Dmitry Peskov said: "I cannot confirm or deny this, even if I wanted to... Whether it is fake or not, we do not know either. There is a lot of fake news these days."

The CNN report did not say when exactly Trump reportedly made the comments about bombing Moscow to Putin.

The Washington Post reported that Trump had spoken to Putin by phone last November - after he won the presidential election but before he returned to the White House - and warned him not to escalate in Ukraine. The Kremlin dismissed reports of the phone call as "pure fiction."

The first acknowledged phone call between the men this year took place on February 12.

Trump, who promised to swiftly end the war in Ukraine, has grown increasingly frustrated with Putin in recent months as the conflict has dragged on.

He directed his ire at the Kremlin chief during a meeting with his cabinet officials at the White House on Tuesday, saying "We get a lot of bullshit thrown at us by Putin". Trump also said he was considering levying additional sanctions on Moscow.

CNN said that Trump also said he had delivered a similar warning to Chinese President Xi Jinping over a potential invasion of Taiwan, telling him that the United States would bomb Beijing in response.