S. Korea, US to work closely on summit after Pyongyang's about-face

South Korean President Moon Jae-in and US President Donald Trump held discussions on Sunday to ensure that the North Korea-US summit remains on track after North Korea threatened to pull out of the high-level talks.

Moon and Trump spoke over the phone for about 20 minutes, and exchanged their views on North Korea's recent reactions, South Korea's presidential office said without elaborating.

"The two leaders will work closely and unwaveringly for the successful hosting of the North Korea- US summit set on June 12, including the upcoming South Korea-US summit," the presidential official said.

Moon and Trump are set to meet on Tuesday in Washington before North Korean leader Kim Jong Un meets with Trump on June 12 in Singapore.