SEOUL-- The U.S. special representative for North Korea, Sung Kim, is expected to visit Seoul later this month for talks with his South Korean counterpart and a trilateral session involving the Russian nuclear envoy, a diplomatic source said Sunday.

Kim is expected to arrive on Saturday for a four-day visit, the source said. It will mark his second trip to South Korea since taking office as Washington's chief nuclear envoy. He last visited Seoul in June.

While Kim is in town, Russia's nuclear envoy, Igor Morgulov, is also expected to visit South Korea for possible trilateral talks with their South Korean counterpart Noh Kyu-duk.

Kim and Morgulov's expected visits come as North Korea has been ramping up pressure on South Korea and the United States over their annual combined exercise that will kick off Monday for a nine-day run.

The Joint Chiefs of Staff announced earlier in the day the two countries will stage the drills in a scaled-back manner in consideration of "the COVID-19 situation, the maintenance of the combined defense posture and the diplomatic efforts for the denuclearization of the Korean Peninsula and the establishment of peace."

When the South and the U.S. started a preliminary exercise on Tuesday, Kim Yo-jong, the sister of North Korean leader Kim Jong-un, blasted the drills as an "unwelcoming act of self-destruction for which a dear price should be paid," and the North began to refuse to answer the South's regular phone calls via their hotlines later that day.

Source: Yonhap News Agency