The national security advisers of the United States, South Korea and Japan have met to discuss North Korea and the "complete denuclearisation of the Korean Peninsula," South Korea says.
South Korea's National Security Office chief, Chung Eui-yong, met US national security adviser HR McMaster and Japan's national security adviser, Shotaro Yachi, to discuss summit meetings between North Korea's Kim Jong-un and South Korean President Moon Jae-in, the Blue House in Seoul said.
They also discussed the possible meeting between Kim and US President Donald Trump.
A senior North Korean diplomat left for Finland on Sunday for talks with former US and South Korean officials, South Korea's Yonhap News Agency reported.
That followed three days of talks between North Korea's and Sweden's foreign ministers on security on the Korean Peninsula.
Sweden "engaged heavily" on the issue of US detainees during the talks between the two foreign ministers, CNN reported on Sunday, citing unidentified sources.
North Korea is pursuing nuclear and missile programs in defiance of UN Security Council sanctions and has made no secret of its plans to develop a missile capable of reaching the US mainland.