SINGAPORE - Asean and China must push and quickly conclude the Code of Conduct in the South China Sea for maritime stability so that the regional grouping can maintain its centrality, said Defence Minister Ng Eng Hen on Monday (Aug 6).

Dr Ng added that the United Nations Convention on the Law of the Sea (Unclos) should also be strengthened, as it is "the legal framework on which both rights of navigation and claims of resources are based on".

Last Thursday, Foreign Minister Vivian Balakrishnan said that Asean and China have agreed on a single text to negotiate the Code of Conduct in the South China Sea.

They have also agreed on the "key modalities" for future rounds of negotiations, said Dr Balakrishnan at the Asean Foreign Ministers' Meeting in Singapore held last week.

On Monday, Dr Ng said that for Asean to maintain its centrality, it must remain "neutral, inclusive and open".

"If Asean member states begin to take sides, assert or close itself to the international community, then its centrality would weaken," he said at the 20th Asia-Pacific Programme for Senior Military Officers organised by the S. Rajaratnam School of International Studies.

He also highlighted areas in trade, connectivity and defence that Asean must focus on in order to maintain its centrality.

For one, Dr Ng called on Asean countries to "eschew national protectionist or nativist trade policies".

Tensions between the United States and China over trade tariffs have escalated recently, after the US' proposal of a 25 per cent tariff on US$200 billion (S$273 billion) worth of Chinese imports.

China has since declared it will retaliate with tariffs on US$60 billion in US goods, and fears of a trade war between the two countries sent Asian stocks tumbling last week.

Dr Ng said that while Asean should work collectively to avoid trade wars or blocs, member states should also continue with multilateral free trade agreements as it has with the European Union and China, such as the Comprehensive and Progressive Agreement for Trans-Pacific Partnership and the Regional Comprehensive Economic Partnership.

Asean must also step up its connectivity, among its members and with the world, said Dr Ng.

Citing how commercial air growth in the region has outpaced that of the world's average air traffic growth rate, Dr Ng said Asean must maintain the conditions for continued growth in air and sea traffic.

"This is the reason why Singapore subscribes to the Code for Unplanned Encounters at Sea for the maritime domain, and as chair of the Asean this year, we will facilitate a Code for Unplanned Encounters for the air," said Dr Ng.

He added that the Qatar diplomatic row in 2017 "can never happen" and "should never happen", as it would cause "lasting damage" to Asean.

Last year, the diplomatic row between Qatar and its neighbours resulted in the severing of travel and trade ties with United Arab Emirates, Saudi Arabia, Egypt and Bahrain.

Dr Ng also called for Asean states to be alert to security threats such as terrorism. He noted how the Marawi conflict in the Philippines, the recent Depok prison riots and the Surabaya bombings in May - both in Indonesia - highlighted how "this threat, if not contained, can escalate and plunge our region into violence and instability".

He added that Asean member states must deal with disputes "through peaceful settlement, as they have done during the Thai-Cambodian border dispute, and Ligitan and Sipadan territorial dispute".

Dr Ng also noted that there are at least three reasons for Asean's centrality.

"First, the alternatives would be worse, collectively and for themselves. All countries understand that tensions would rise, if any large or even middle powers asserted themselves to change the status quo to gain central dominance," he said.

The second reason is that Asean member states are located in two key maritime domains - the South China Sea and the Straits of Malacca - which are "vital to global trade".

The third reason, said Dr Ng, is that "the values of Asean provide comfort and assurance to larger powers" as it is "neutral, inclusive and open".

If Asean manages to maintain its centrality, the region will see continued growth in population, commercial air traffic, sea traffic and digital traffic, "which could potentially add US$1 trillion to Asean's gross domestic product in the next decade alone".

He added: " It would be an Asean with all of its ten capital cities put up as models of emerging and developed economies for the rest of the world."