South Korea’s chief nuclear envoy has admitted it remains to be seen whether working-level negotiations between the U.S. and North Korea will resume in two weeks as Washington hopes. 

Lee Do-hoon, Seoul's special representative for Korean Peninsula peace and security affairs, made the remark to reporters at Incheon International Airport on Thursday upon his return from a three-day trip to the U.S. for talks with his American and Japanese counterparts. 

After the latest U.S.-North Korea working level talks collapsed in Stockholm last weekend, the U.S. government said it had accepted the Swedish government’s invitation to resume talks with the North in two weeks. Pyongyang, however, has expressed skepticism that talks can happen so soon. 

Lee said he was briefed by his U.S. counterpart Stephen Biegun on the Sweden talks, but declined to elaborate, saying they had in-depth conversations about how the two allies will cooperate over related matters.

He added they plan to continue discussing follow-up actions depending on any changes in the situation.