Except for South Korea and the United States, the UNC currently has 16 sending states that are to provide combat troops, equipment and other forms of support in case of a contingency on the peninsula.

The sending states include Australia, Belgium, Canada, Denmark, France, Italy and New Zealand. They have posted their contingents at the UNC to support its operations centering on the observance and enforcement of the armistice that halted the 1950-53 Korean War.

The pursuit of Japan's entry into the UNC comes amid heightened tensions between South Korea and Japan, which were caused by Tokyo's recent export control measure seen as a retaliatory move for last year's Supreme Court rulings here against Japanese firms over wartime forced labor.

As part of its "revitalization" efforts, the UNC has been seeking to beef up its operational structure with more contributions from its 16 sending states -- excluding South Korea and the US -- and efforts to include more outside participation.

"I know that the UNC is working at seeing if other nations are interested in joining, but it is also in the works. Nothing has been confirmed," a UNC official told Yonhap News Agency over the phone.

It remains unclear whether Japan would accede to a call to join the UNC, as any possibility of Tokyo's military involvement on the peninsula could further exacerbate strained relations with Seoul.

Japan is already home to a number of UNC rear bases that would be mobilized in the event of a crisis in Korea.

Since 2014, the UNC has been pushing for the revitalization campaign to ostensibly deepen its commitment to "maintaining stability and peace in Korea by employing multinational forces of the sending states," it has said.

As part of the campaign, the UNC has strengthened its staff by securing more contributions from member states and having senior officials exclusively dedicated to their UNC roles rather than taking other responsibilities.

The campaign has been picking up pace amid the intensifying Sino-US rivalry, talks for Washington's envisioned transfer of wartime operational control to Seoul and efforts for a lasting peace regime on the peninsula that could render the UNC obsolete.

Analysts said that the initiative appears aimed at ensuring the UNC's readiness for military contingencies, enhancing America's influence over the peninsula or preserving the US-led regional security order challenged by an assertive China. (Yonhap)