This combination of file photos created on January 16, 2017, shows US President-elect Donald Trump on December 16, 2016 in Orlando, Florida and Russian President Vladimir Putin on October 19, 2016 in Berlin. AFP-Yonhap

U.S. President Donald Trump urged Russian President Vladimir Putin on Friday to help keep pressure on North Korea until it dismantles its nuclear weapons program, Trump's spokeswoman said.

The two leaders spoke by phone and discussed nuclear agreements, trade, and the political situations in North Korea, Ukraine and Venezuela, according to White House press secretary Sarah Sanders.

"They spoke about North Korea for a good bit of time on the call and reiterated both the commitment and the need for denuclearization," Sanders told reporters at the White House.

"And the president said several times on this front as well the need and importance of Russia stepping up and continuing to help and put pressure on North Korea to denuclearize," she said. "And that was again the focus of the president's comment on that front."

Putin held his first summit with North Korean leader Kim Jong-un in Russia's Vladivostok last month.