South Korea and the United States are set to hold a "two plus two" meeting of foreign and defense ministers later this week, with a key focus on reinvigorating their alliance in the face of a recalcitrant North Korea and an assertive China.

Foreign Minister Chung Eui-yong and Defense Minister Suh Wook will join their US counterparts, Antony Blinken and Lloyd Austin, for the allies' first such gathering in five years on Thursday after they hold separate two-way meetings with their respective counterparts on Wednesday.

The meeting comes as the administration of US President Joe Biden seeks to leverage what it calls America's "greatest strategic asset" -- alliances with South Korea, Japan and others -- to uphold a "free and open" Indo-Pacific region being challenged by a rising China.

The high-profile gathering was instituted in 2010 to stress the robustness of the alliance after the North's deadly torpedo attack on the South's corvette Cheonan. Though it started as a regular dialogue platform, it has not been held since the last and fourth session in Washington in October 2016.

The North's nuclear issue is expected to top the agenda for this week's session as the US may complete a review of policy on Pyongyang in the coming weeks, as Sung Kim, acting assistant secretary of state for East Asian and Pacific affairs, said in a press briefing last week.

The two sides have been coordinating on the policy review amid signs of activity at the North's main Yongbyon nuclear complex, while heading off its saber-rattling that could flare up amid an ongoing military exercise between the allies set to end Thursday.

They are also expected to discuss the strengthening of their alliance that had faced uncertainty due to former US President Donald Trump's transactional way of diplomacy based on his inward-looking "America-first" vision.

The Biden administration' choice of South Korea and Japan as the destinations of its first Cabinet-level overseas trip underscores its resolve to "reinvigorate and modernize" America's democratic alliances, observers noted.

"Our work with Japan and South Korea covers a vast range of issues that are critical to our security and prosperity -- and to the world's," Blinken and Austin wrote in a joint contribution to the Washington Post ahead of their trip to Asia.

"Our diplomats and defense leaders strategize together on how to confront shared threats such as North Korea's nuclear weapons and ballistic missile programs. We stand together in support of democratic values and will do so strongly wherever they are challenged," they added.

In line with the alliance reinforcement scheme, Blinken and Austin are expected to try to promote reconciliation between Seoul and Tokyo, which are caught in persistent historical rows, and trilateral cooperation with the Asian allies. In a fact sheet on the US-Japan alliance, which the State Department released Sunday, the US reiterated its commitment to that end.

"No relationship is more important than that between Japan and the Republic of Korea (ROK)," the department wrote in the fact sheet.

"The United States continues to promote expanded US-Japan-ROK cooperation to tackle COVID-19 and combat climate change, as well as reinvigorate trilateral cooperation on a broad range of global issues, including the denuclearization of North Korea," it added.

The agenda may also include such bilateral issues as slower-than-expected preparations for the envisioned handover of wartime operational control and the broadening of their partnership to jointly tackle climate change and global health crises.

China-related issues could figure prominently in the talks, as the US angles for a coalition of like-minded countries to counter the growing influence of China.

The Biden administration could seek Seoul's role in addressing alleged human rights abuses in China's Xinjiang Uighur autonomous region, crackdowns on pro-democracy protesters in Hong Kong and Beijing's claims to the lion's share of the South China Sea.

The potential call to stand against Beijing could pose a nettlesome geopolitical dilemma to Seoul, as it has been walking a tight rope between its traditional ally, the US, and top trading partner, China.

"Regarding Xinjiang, I think you have heard on many occasions the Secretary express his deep concerns about the egregious human rights violations that are happening in Xinjiang," Sung Kim has told reporters. "I believe our partner -- our allies share our concerns, and so I expect that the topic of Xinjiang will come up in both Seoul and Tokyo."

At Thursday's meeting, Seoul and Washington plan to adopt a joint statement to present the future direction of their alliance, a foreign ministry official said.

"The joint visit to South Korea by the secretaries of state and defense reflects the strong will of the Biden administration to restore alliances and its leadership vis-a-vis global pending issues through cooperation with the allies," the official told reporters.

"Our assessment is that the inclusion of South Korea in their first overseas trip reaffirms the importance and firmness of the alliance between the two countries," he added.

Following the meeting, South Korea's top negotiator, Jeong Eun-bo, and Rob Rapson, acting US ambassador to Seoul, will initial a recently concluded deal on Seoul's share of the cost for stationing the 28,500-strong US Forces Korea in a symbolic event underscoring the alliance.

This week's Asia trip by Blinken and Austin will cap a weeklong campaign to highlight the US' efforts to strengthen partnerships with allies and partners to promote a "free, open rules-based order," which started off in the first leader-level session of the Quad forum involving Japan, Australia and India.

The US has two-plus-two platforms only with Australia, Japan, South Korea and India, which were launched in 1985, 1990, 2010 and 2018, respectively. (Yonhap)