The top US envoy for North Korea will visit Seoul this weekend, with his arrival delayed a day for an unspecified reason, an informed source said Friday.

Sung Kim, a special representative for North Korea, was initially scheduled to begin a three-day trip here on Friday for consultations with his South Korean counterpart, Noh Kyu-duk, Yonhap news agency reported.

However his itinerary has changed, and he plans to fly to Seoul on Saturday, according to the source, who requested anonymity and did not elaborate on the reason.

Kim and Noh are widely expected to meet again Sunday and continue discussions on pending issues related to the Korean Peninsula, including South Korean President Moon Jae-in’s proposal to declare a formal end to the 1950-53 Korean War, as Seoul and Washington step up diplomacy to revive long-stalled talks with the reclusive regime.

Seoul hopes to use the declaration as a stepping stone to improve cross-border relations and achieve lasting peace on the peninsula.

“The end-of-war declaration is one of several options to restart the peace process,” Foreign Minister Chung Eui-yong told lawmakers during a parliamentary audit Wednesday. “It is the first gateway for the peace process on the Korean Peninsula and an essential step.”

Pyongyang has sent mixed signals regarding a possible return to dialogue, firing a submarine-launched ballistic missile Tuesday — its eighth known major missile test this year.

The North, however, backed off from further ratcheting up tensions as its foreign ministry spokesperson said the launch was not aimed at the United States.

Kim and Noh met in Washington on Monday for consultations on North Korea. They were joined by their Japanese counterpart, Takehiro Funakoshi, the following day for trilateral discussions where the three agreed to work closely together to restart the peace process on the peninsula at an early date.

Denuclearisation talks between Washington and Pyongyang remain stalled since the no-deal Hanoi summit in 2019, although the Joe Biden administration has maintained that it is willing to meet with the North “without preconditions.”