South Korean officials who visited Pyongyang recently say North Korean leader Kim Jong Un agreed to hold talks with South Korean President Moon Jae-in in late April. Seoul says Kim also proposed meeting with President Donald Trump — and has committed to denuclearization talks. Trump agreed to meet Kim by the end of May.

The developments have raised hopes for a potential breakthrough in the North Korean nuclear crisis. But many experts say tensions would flare again if the summits fail to make any progress and leave the nuclear issue with few diplomatic options.

U.S. National Security Adviser H.R. McMaster met his South Korean and Japanese counterparts, Chung Eui-yong and Shotaro Yachi, in San Francisco for talks over the weekend on denuclearization and the summits, South Korea's presidential office said in a statement.