Russian President Vladimir Putin remained open to contacts with U.S. President Donald Trump, Kremlin spokesman Dmitry Peskov said on Monday.

A telephone conversation between Putin and Trump is not scheduled yet, Peskov said, adding that "such contacts can be agreed upon very quickly if necessary."

He noted that Russia and the United States were working on implementing ideas related to the Ukrainian settlement, but there were no specifics yet.

In a phone interview with NBC News on Sunday, Trump said he was "very angry" and "pissed off" when Putin criticized the credibility of Ukrainian President Volodymyr Zelensky's leadership, adding that the comments were "not going in the right location."

Trump said Putin knows he is angry, but he has "a very good relationship" with Putin and would speak to the Russian leader again.