Representatives from the United States and North Korea are reportedly meeting in Finland for “second-tier” talks on denuclearization.

Few details are available, but the meeting was confirmed to CNN by the Finnish and South Korean foreign ministries, and the South Korean news agency Yonhap reported that the North Korean official responsible for US affairs was spotted at the Beijing airport heading to Finland.

A Finnish official told CNN that the talks would be a “track 1.5 academic meeting,” which means that it will involve government representatives and outside experts. It’s unclear who the experts will be, but Yonhap reported that Kathleen Stephens, former US ambassador to South Korea, is slated to attend.

The meeting would come ahead of the US-North Korean summit between the leaders of the two countries, planned for May. The New York Times reported earlier this month that a possible location is a conference building in the demilitarized zone between North and South Korea.

Donald Trump agreed to the summit in a snap decision during a March meeting with a South Korean envoy in the White House, to the world’s astonishment. It would be the first meeting between a sitting US president and North Korean head of state, and it comes after the two leaders exchanged blustering threats. Since the announcement, North Korea has fallen silent, raising questions about the summit’s certainty. Reports of the Finnish meeting signal progress.

Separately, North Korea and Sweden concluded on Saturday in Stockholm talks on security, which CNN reported also focused heavily on the issue of American citizens held captive by the former country.