The top nuclear envoys from Russia and the US are in Seoul to hold talks with their South Korean counterpart on the stalled nuclear diplomacy with Pyongyang amid fresh tension over ongoing US-South Korea military exercises.

Sung Kim, the US special representative for North Korea, arrived here Saturday for a four-day visit, days after Pyongyang warned of a “security crisis” over the joint military drills that are due to end Thursday.

“I’m looking forward to very close consultations with our Korean government colleagues,” Kim told reporters upon arriving at Incheon Airport.

Kim said he will also meet with Russia’s Deputy Foreign Minister Igor Morgulov, who arrived here Saturday for a six-day visit.

“So, I think it is going to be a very productive visit,” said Kim.

Kim met with Foreign Minister Chung Eui-yong on Sunday afternoon and discussed ways to restart the stalled peace process on the Korean Peninsula at an early date.

On Monday, Kim is set to meet with Seoul’s chief nuclear envoy, Noh Kyu-duk, to discuss how best to cooperate to achieve substantive progress toward complete denuclearization and lasting peace on the Korean Peninsula, according to the Foreign Ministry.

The State Department, in a separate statement, said Kim’s trip illustrates the allies’ commitment to “ongoing close collaboration on DPRK issues as we seek to advance complete denuclearization and permanent peace on the Korean Peninsula.” The DPRK stands for North Korea’s official name, the Democratic People’s Republic of Korea.

Morgulov, who doubles as the point man on North Korea, is scheduled to meet with Noh on Tuesday to discuss ways to bolster cooperation toward denuclearization and peace on the peninsula.

No three-way meeting between the US, Russia and South Korea has been arranged yet, according to a ministry official. Such a meeting has been the subject of much speculation.

All eyes are on what message the US and Russian envoys will send to the recalcitrant regime and what ideas will be proposed to bring Pyongyang back to the negotiating table.

The momentum for a thaw in soured inter-Korean ties was short-lived after Pyongyang slammed the joint drills as the most “intensive expression of the US hostile policy” toward Pyongyang and an “unwelcoming act of self-destruction for which a dear price should be paid,” as the allies kicked off a preliminary exercise Aug. 10. On the same day, Pyongyang also refused to answer routine calls on inter-Korean hotlines and has been unresponsive since. The hotlines were restored July 27 after a yearlong halt amid strained ties.

The sudden resumption in inter-Korean channels -- the outcome of a series of letters exchanged between South Korean President Moon Jae-in and North Korean leader Kim Jong-un -- has raised hopes for a thaw in inter-Korean ties as well as improved US-North Korea relations.

Denuclearization talks stalled during the previous Trump administration after the collapse of the Hanoi summit in 2019, when former US President Donald Trump rejected Kim Jong-un’s offer of major sanctions relief in exchange for North Korea’s denuclearization. Since then, inter-Korean ties have also remained at a standstill.

Sung Kim said during his last visit in June that the US is willing to meet North Korea “anywhere, anytime without preconditions,” but Pyongyang has rebuffed Washington’s diplomatic overtures.