SEOUL, The U.S. envoy for North Korea returned to South Korea on Friday following a three-day visit to Pyongyang.

A U.S. military plane presumed to be carrying Stephen Biegun landed at the U.S. air base in Osan, south of Seoul, around 7:00 p.m.

He has been in North Korea since Wednesday, following his arrival in the South at the weekend to prepare for a summit between Pyongyang and Washington.

His mission was to work out agenda and logistical details of a second summit between President Donald Trump and North Korean leader Kim Jong-un to take place in Vietnam from Feb. 27-28. Biegun's new North Korean dialogue partner was reportedly Kim Hyok-chol, former ambassador to Spain.

A South Korean foreign ministry official earlier told reporters that Biegun has promised to provide the South Korean government with a quick briefing on the results of the working-level talks in Pyongyang.

Chances are high that he will meet again with Seoul's top nuclear envoy, Lee Do-hoon, early Saturday morning.

Source: Yonhap news Agency