US President Donald Trump has declined to comment on a media report that he discussed the war in Ukraine with Russian President Vladimir Putin over the phone, but said he believes "we're making progress."

While on board Air Force One on Sunday, Trump was asked by reporters about an interview he did with the New York Post on Friday.

The tabloid reported that the president had spoken with Putin on the phone to try to negotiate an end to the Russian invasion of Ukraine.

Trump was also asked by reporters to clarify whether he had the conversation before or after he took office.

He answered, "Let's just say I've had it and I expect to have many more conversations."
He went on, "We have to get that war ended."

On a possible summit with Putin in person, Trump said he would be meeting with the Russian leader "at the right time, at the appropriate time."

Trump has repeatedly expressed his willingness to bring an early end to the conflict in Ukraine.

He says he plans to talk with both Ukrainian President Volodymyr Zelenskyy and Putin on ending the war.