US President Joe Biden's special envoy for North Korea, Sung Kim, arrived in South Korea on Saturday for discussions over stalled nuclear diplomacy with Pyongyang.

Sung Kim's visit comes amid fresh tensions over ongoing US-South Korean military exercises, which the North has described as an invasion rehearsal and led to it threatening unspecified countermeasures that would leave the allies facing a “security crisis.” Kim will meet his South Korean counterpart, Noh Kyu-duk, on Monday and also plans to hold separate talks with Russian Deputy Foreign Minister, Igor Morgulov, who also arrived in Seoul on Saturday.

South Korea's Foreign Ministry and the US State Department didn't immediately mention any plan for three-way talks with the Russians.

Also see: South Korea seeks to improve ties despite North’s threat

The State Department said Kim's meetings with Noh and South Korean officials are aimed at discussing the “situation on the Korean Peninsula and continue close coordination on the way forward.”

“I'm looking forward to very close consultations with our Korean government colleagues,” Kim told reporters at the Incheon international airport.

US-SK drills

The Untied States and South Korea began a nine-day joint military exercise on Thursday, which Seoul's Defence Ministry said is mostly computer-simulated and won't involve live field training. There have been no known missile tests by North Korea since the start of the drills, although South Korean military officials have said the North is currently staging its own summertime exercises.

North Korea has long bristled at the US-South Korea military drills, which the allies say are routine and defensive in nature, and often responds to them with its own weapons demonstrations. The allies in the past few years have cancelled or downsized some of their joint training to provide space for diplomacy or because of the Covid-19 pandemic.

Last week, Kim Yo Jong, the powerful sister of the North Korean leader Kim Jong Un, released a statement saying that the joint drills were the “most vivid expression of the US hostile policy” toward North Korea and said the North will work faster to strengthen its pre-emptive strike capabilities.

Some analysts say the North's threat may signal a resumption of its weapons testing activities. North Korea ended a yearlong pause in ballistic tests in March by firing two short-range missiles into the sea, continuing a tradition of testing new US administrations with weapons demonstrations aimed at measuring Washington's response and wresting concessions.

But there haven't been any known test launches since then as Kim focused national efforts on fending off the coronavirus and salvaging a broken economy damaged further by pandemic border closures.

Talks between the United States and North Korea have stalled since the collapse of a summit between former President Donald Trump and Kim in 2019, when the Americans rejected the North's demand for major sanctions relief in exchange for a partial surrender of its nuclear capabilities.

Kim has since pledged to bolster his country's nuclear deterrent while urging his people to stay resilient in a struggle for economic self-dependence in the face of US pressure. His government has so far rejected the Biden administration's overtures for talks, demanding that Washington abandon its “hostile” policies first.

The North's State media said Saturday that Kim inspected a construction site for new riverside apartments in Pyongyang and described the project as crucial in making the capital “more modern and civilized.” The report didn't make any comments toward the United States or South Korea.