U.S. Special Representative for North Korea, Stephen Biegun, arrived in Seoul on Sunday for talks with his South Korean counterpart about the ongoing diplomatic efforts with North Korea.
Biegun's trip comes only a week after South Korea's own nuclear envoy Lee Do-hoon visited Washington.
It's expected that the two representatives will discuss the progress made so far towards North Korea and the U.S. holding high-level and working-level talks.
They'll also likely analyze Pyeongyang's latest moves, such as its vice foreign minister's visit to Russia.
They're also expected to discuss how sanctions fit into inter-Korean cooperation plans like building railroad connection and forestation -- areas where those plans violate international sanctions... and where there need to be exemptions.