With the regional security forum in Vientiane, Laos, drawing to a close, South Korea, the U.S., China and other countries on Tuesday stepped up diplomatic efforts to carry through their claims on pressing issues.

The 27 foreign ministers took part in the ASEAN Regional Forum’s plenary and retreat sessions, delivering speeches and conversing with one another in between.

At stake is a chairman’s statement to be presented as the upshot of the conference, which will address various regional security challenges including North Korea’s nuclear program, the South China Sea dispute and terror threats from extremist groups.

China has reportedly been pushing to reflect in the document its opposition to the plan to deploy the U.S.’ Terminal High Altitude Area Defense system in South Korea. A draft seen by Japan’s NHK broadcaster read “multiple ministers expressed concerns” about the project, and “most ministers expressed serious concerns” over the North’s recent series of ballistic missile tests.

If the THAAD-related phrase survives in the final version, it would mark another diplomatic coup for Beijing, which has managed to block an earlier ASEAN joint statement from taking note of a recent international tribunal’s ruling rejecting its territorial claims in the South China Sea.

Seoul, in turn, could face stiff backlash at home for its failure to secure understanding not only from the residents of the deployment site at home but also the neighbor it has been boasting “best-ever” ties with.

“So far the THAAD issue has not been directly brought up but after the later session the host country will reflect the results in the draft, which was made on the assumption of what was to be discussed,” a senior official of Seoul’s Foreign Ministry told reporters in Vientiane in the afternoon ahead of the ARF meeting. 

He refused to elaborate on the content of the text because it was “inappropriate to speak about a particular nation’s stance” and several versions of the draft would be circulated.

“But on the North Korean issue mostly there’s consensus,” he noted.

The seemingly heated debates on several fronts may prompt the negotiation to drag on for days, the ministry official suggested, pointing to the pattern shown over the past few years. Last year’s script came four days after the forum ended in Kuala Lumpur.

In the 2015 statement, the ministers called for deescalating tension, refraining from taking any “counterproductive moves,” and “constructive engagement” to restart the stalled six-party talks for the denuclearization of the peninsula. Most ministers -- meaning except for the North -- urged the communist state to comply fully with its international obligations.

This time, South Korean Foreign Minister Yun Byung-se would call for the member states to impose greater concerted pressure on Pyongyang against its military ambitions.

The session also set the stage for the debut on the international arena of Ri Yong-ho, who took up the chief diplomatic job last May. He was expected to deride Washington and its allies for what it calls their “hostile policy” and demand recognition as a nuclear weapons state through his own address.

In his opening remarks at a separate ASEAN+3 meeting earlier in the day, Yun listed the North’s fourth atomic experiment early this year as one of the “destabilizing factors” for the global security landscape, alongside terrorism and Brexit.

Top diplomats of the 10-nation Southeast Asian bloc issued a joint communique late Monday in which they urged Pyongyang to abide by U.N. Security Council resolutions while calling for efforts to reopen the six-nation forum.

Unlike the ASEAN document, however, the ARF statement could carry a relatively softer language given the participation of North Korea and China as well as its traditional partners such as Cambodia which had helped China push through its position on the South China Sea in the former case.

Laos, the host country, also has decades-old relations with the North including robust party-to-party exchanges. Speculation is rampant that Ri may be slated for a separate high-profile diplomatic schedule as he is believed to be staying in the country until Thursday.

But another Seoul diplomat downplayed the view, saying the Southeast Asian nation acknowledges the “sensitivity” that might arise from intensive bilateral engagement at this point.

By Shin Hyon-hee (heeshin@heraldcorp.com)