The chief envoys of the U.S. and North Korea continued their final round of working-level negotiations ahead of the upcoming second U.S.-North Korea summit in Hanoi. 

U.S. Special Representative for North Korea Stephen Biegun and his North Korean counterpart Kim Hyok-chol held talks on Sunday at a hotel in Hanoi where Biegun is staying. 

Choe Kang-il, acting head of the North American department of North Koreas’ Foreign Ministry, and Kim Song-hye, head of strategy at the United Front Department(UFD) of the ruling Workers’ Party, also attended the talks, which began at 2:30 p.m. and lasted for over two hours.

The top envoys held pre-summit negotiations for the fourth consecutive day since arriving in Vietnam on Wednesday. 

The two sides are believed to be in intense negotiations to fine-tune details for a summit declaration, which would include the North’s steps to denuclearization and the U.S.’s corresponding measures.