BEIJING - Chinese President Xi Jinping has assured South-east Asian leaders that China does not seek hegemony and will not bully its smaller neighbours, even while tensions in the South China Sea have escalated.

At a special summit held virtually on Monday (Nov 22) between the top leaders of China and the Asean states to mark 30 years of dialogue relations, Mr Xi also pledged aid in terms of Covid-19 vaccines and funds to support the grouping's pandemic response.

The meeting comes after a skirmish in the South China Sea last week (Nov 16) that involved the Chinese Coast Guard blocking boats carrying supplies to the Philippine military in the disputed Spratly Islands, and firing a water cannon on the vessels.

The incident, which China says was an act of defence of its sovereignty, drew strong protest from the Philippine government and a warning from the United States that it would come to its ally's aid if an armed attack is launched.

Philippine President Rodrigo Duterte took the opportunity at the virtual summit to condemn the act. "We abhor the recent event in the Ayungin Shoal and view with grave concern other similar developments," he said, adding that the episode "does not speak well of the relations between our nations and our partnership".

It is not clear if Mr Xi responded to Mr Duterte's remarks, but he had cordial words for the Asean leaders and emphasised the bloc's high priority in China's regional relations.

"China was, is, and will always be Asean's good neighbour, good friend and good partner," he told the bloc's leaders through a video link, according to a readout released by state news agency Xinhua.

China will "unswervingly" support Asean unity and centrality, as well as the grouping playing a bigger role in regional and international affairs, said the Chinese leader.

To maintain peace in the region, countries need to pursue dialogue instead of confrontation, he added.

"China will never seek hegemony, much less bully smaller countries."

The South-east Asian nations will receive 150 million doses of Covid-19 vaccines, and also an injection of US$5 million (S$6.8 million) into their joint Asean Response Fund, Mr Xi said.

China is also ready to offer Asean US$1.5 billion in development assistance in the next three years to support its fight against Covid-19 and speed up economic recovery.

It, too, will work with the Asean states to step up vaccine joint production, collaborate on the research and development of medicine, and help the South-east Asian countries build better capacity to respond to major public health emergencies.

As the leaders marked the milestone in relations on Monday, they also gave it an upgrade to a "comprehensive strategic partnership" status, which allows for deeper collaboration between the parties.

Singapore Prime Minister Lee Hsien Loong said Asean and China should look at how to progressively open up their borders to one another as vaccination rates improve across the region.

The leaders at the summit also discussed upgrading their free trade area, signed in 2002, and the roll-out of the bigger and newer trade pact, the Regional Comprehensive Economic Partnership (RCEP), which Malaysian Prime Minister Ismail Sabri Yaakob in a statement at the meeting said could help speed up regional recovery.

Signed in November 2020 and coming into force in January 2022, RCEP is a mega trade deal involving Asean's 10 member states and its five free trade agreement partners: China, Japan, South Korea, Australia and New Zealand.

China is Asean's largest trading partner, with bilateral trade reaching US$410.75 billion in the first half of this year alone, and accounting for almost 15 per cent of China's total foreign trade, said Beijing.

Mr Xi on Monday promised to buy up to US$150 billion worth of agricultural products from Asean in the next five years; China will also support an exchange programme for 300 young scientists from the region to visit over the same period.

Both sides issued a joint statement after the meeting, which, among other things, reaffirmed the principles of the Asean Outlook on the Indo-Pacific, the bloc's own Indo-Pacific vision.

China has all along been averse to this term, which reconceptualises the region and the East Asian giant's dominance in it.

The statement also reaffirmed the importance of upholding international law including the 1982 United Nations Convention on the Law of the Sea, and a commitment to the freedom of navigation in and flights over the South China Sea.

Glaringly missing from the high-level summit was Myanmar junta chief Min Aung Hlaing, as Asean leaders held firm on their consensus that the country send a non-political representative.

China had lobbied for the Myanmar general to attend, but Asean leaders objected. They first want to see progress on an agreement to let in an Asean special envoy into Myanmar to help mediate a peaceful solution to the violent military coup staged in February.

When asked about Myanmar's absence, Chinese Foreign Ministry spokesman Zhao Lijian would say only that the meeting was a success, thanks to the efforts of China, Myanmar, the Philippines and other countries.

Myanmar is an important member of the Asean family, and China supports Asean centrality and the five-point consensus agreement it struck with Myanmar, he said.

Myanmar is the coordinating country for Asean-China relations this year.

Chinese state media later reported that the Chinese ambassador in Myanmar had briefed the country's foreign minister on the summit.

It said the Foreign Minister, Mr Wunna Maung Lwin, remarked that Myanmar was "pleased with the success of the summit", and that it had made "due efforts for the outcome of the summit and will continue to play the role of a coordinating country".