Former US President Donald Trump has refused to call Russian President Vladimir Putin a war criminal because, according to him, it could harm negotiations with the Russian Federation.

When a journalist asked if Trump considered the Russian president a war criminal, he said: "I think it should be discussed later."

"If you say he’s a war criminal it’s going to be a lot tougher to make a deal to make a deal to get this thing [the war – ed.] stopped," Trump said during a debate on CNN.

The former US president believes that the charges against Putin should be discussed "later".

Trump called the Russian dictator "very smart" and "very cunning." At the same time, he believes that Putin made a tremendous mistake by attacking Ukraine.

"His mistake was going in. He would have never gone in if I was president," Trump added.

Previously, Donald Trump had refused to answer the thrice-voiced question of who he wants to see as the winner in Russia's war against Ukraine.