Foreign ministers of the Association of Southeast Asian Nations meeting in Singapore on Thursday discussed North Korea's nuclear weapons program and developments relating to disputes in the South China Sea involving China and some of the grouping's members.

The meeting comes as tensions on the Korean Peninsula have eased since a historic summit between U.S. President Donald Trump and North Korean leader Kim Jong Un in Singapore on June 12, although Pyongyang has yet to take concrete and credible measures to rid itself of weapons and ballistic missiles.

In the joint communique issued after the meeting, the foreign ministers welcomed the North Korean leader's commitment to "complete" denuclearization in a joint statement he signed with Trump during the first-ever U.S.-North Korea summit.

While noting Pyongyang's pledge to suspend further nuclear and missile tests, the ministers expressed ASEAN's support for achieving complete, verifiable and irreversible denuclearization of the Korean Peninsula, the document says.

In veiled criticism of China's militarization of disputed features in the South China Sea, the ministers emphasized the importance of "non-militarization and self-restraint" in the conduct of all activities in the disputed waters.

At the same time, they were encouraged by progress in substantive negotiations between the 10-member ASEAN and China toward the early conclusion of an effective code of conduct, or COC, in the sea on a mutually agreed timeline, the draft says.

Progress has been made by ASEAN and China, with the two sides agreeing on a "single draft COC negotiating text" when senior officials of the two sides met in Changsha, China, on June 27.

The agreement was officially announced by Singaporean Foreign Minister Vivian Balakrishnan during the ASEAN-China meeting later Thursday, saying the document will be the basis of future COC negotiations.

"Everyone also hopes that we will be able to accelerate the process, but we are not yet in a position to put a specific deadline," Balakrishnan told a press conference after the daylong meetings.

According to an ASEAN diplomat, negotiations for the first draft will commence in September by an ASEAN-China joint working group in Siem Reap, Cambodia. The basic elements of the draft that need to be filled in include "objectives, principles, and kind of activities."

"The single document has made our works easier because we have already had one single foundation," Indonesian Foreign Minister Retno Marsudi told Indonesian reporters.

"We are negotiating one document only and we have even successfully completed the preamble," she said. "In the next meeting, we will discuss other chapters. However, the single document has made it easy for us to negotiate."

Asked if the negotiations will address whether or not the COC will be legally binding, the diplomat, who requested anonymity, said, "We're not there yet. The paper doesn't mention 'legally binding,' but there are some proposals connected to that."

"We want an effective code. That's the most important thing," the official added.

Thai Foreign Minister Don Pramudwinai called the text "a significant breakthrough."

"Despite some differences in the text, at least ASEAN and China can go on the same track to find a 'common text' on the COC," Don said.

China has claims in the South China Sea, a strategic waterway through which over one-third of global trade passes, that overlap those of Brunei, Malaysia, the Philippines and Vietnam, as well as Taiwan,

The ministers also discussed issues such as counterterrorism, human rights and economic integration, especially the Regional Comprehensive Economic Partnership, a free trade initiative involving 16 economies including ASEAN, Japan, China and Australia.

In his remarks at the meeting's formal opening, Singapore Prime Minister Lee Hsein Loong called on ASEAN to do more on its economic integration efforts and other economic goals amid global trade tensions, as well as to make full use of technology to enhance development.

ASEAN, having "achieved its initial political objective of regional peace and stability," has "shifted its focus to economic cooperation," Lee said.

"While these ASEAN-led structures have served us well, we must continue to strengthen the regional architecture. We can all see the growing geopolitical uncertainties," he said.

Noting escalating trade tensions between the United States and China, and with other countries, Lee said, "It is important that ASEAN continues to support the (rules-based multilateral trading) system and work with like-minded partners to deepen our web of cooperation."

The annual foreign ministerial meeting is being hosted by Singapore, which holds the rotating chairmanship of ASEAN this year. Related meetings involving ASEAN members and their partner countries will run until Saturday.

On the issue of over 720,000 Rohingya refugees in Bangladesh, the ministers "underlined the importance of the expeditious commencement of the voluntary return of displaced persons to Myanmar in a safe, secure and dignified way, without due delay," the joint communique said.

They also "welcomed the establishment of an Independent Commission of Enquiry by the government of Myanmar."

Subsequent ASEAN-related meetings to be held in Singapore through Saturday will include foreign ministers from Australia, Canada, China, India, Japan, New Zealand, Russia, the United States and the two Koreas.

World leaders such as U.S. President Trump and Russian President Vladimir Putin are expected to gather in this city-state in November for a larger ASEAN-led summit.

ASEAN groups Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam.