The Swedish government is reportedly negotiating with North Korean officials to secure the release of three American citizens being held captive in the country. Sources familiar with the talks told CNN on Sunday that Sweden’s foreign minister, Margot Wallström, “engaged heavily” in the issue of the Americans’ release during a meeting with North Korean Foreign Minister Ri Yong Ho in Stockholm this weekend. Two of the U.S. citizens currently being held, Kim Hak-song and Kim Sang-duk, were imprisoned in 2017 after being accused of “hostile acts.” The third prisoner, Kim Dong Chul, was arrested in 2015 and is serving a 10-month sentence for alleged espionage. Sweden’s talks with the North Korean foreign minister come amid a spate of diplomatic meetings thought to be aimed at organizing a summit between President Trump and North Korean leader Kim Jong Un. A top North Korean diplomat, Choe Kang Il, also headed to Finland on Sunday to meet with former U.S. and South Korean officials ahead of that planned meeting.