U.S. President Donald Trump was scheduled to speak by telephone with Prime Minister Shinzo Abe and Chinese leader Xi Jinping on Sunday evening in talks that were likely be centered around North Korea's nuclear program.

The White House said Saturday that the calls would take place starting at 8 p.m. Sunday but did not elaborate on the subject of the conversations.

North Korea's missile and nuclear development programs have been one the Trump administration's top foreign policy issues as it seeks to rein in the isolated regime of dictator Kim Jong Un.