U.S. President Donald Trump has said that he doesn't know what exactly is happening in Ukraine, but said he will find out.

"We don't know really exactly what that is," Trump said in an interview with Fox News.

When asked by the host if he took it as an insult that 24 hours after his telephone conversation with Russian President Vladimir Putin, the pro-Russian forces stepped up violence in Ukraine, Trump said he did not, because he doesn't know if the forces in Ukraine's east are really controlled by Russia. However, the U.S. president promised to find out if that is the case.

"We gonna find out. I'd be surprised, but we'll see," the president said.

Trump also said he respects Putin but that doesn't necessarily mean they will get along.

"He's the leader of his country. I say it's better to get along with Russia than not. Will I get along with them, I have no idea," the U.S. president said.