SINGAPORE — With two-thirds of all maritime trade projected to be shipped across the South China Sea, a single disruption or interruption would have unforeseeable consequences to the entire world, said Vietnamese Prime Minister Nguyen Tan Dung yesterday.

Unpredictable developments in the Korean Peninsula and sovereignty and territorial disputes from the East China Sea to the South China Sea are evolving with great complexity, threatening regional peace and security and causing deep concern to the international community, said Mr Dung, who was delivering the keynote address at the 12th Shangri-La dialogue.

Mr Dung called on the United States and China to play a greater role in, and contribute more to the region, noting that the powers’ involvement in the region would contribute not only to their interests but to the region’s.

Pointing out that “small and medium countries could help lock major powers into a durable regional architecture” — a view he said he shared with Indonesian President Susilo Bambang Yudhoyono, Mr Dung said: “I believe that no regional country would oppose the strategic engagement of extra-regional powers if such engagement aims to enhance cooperation for peace, stability and development.”

Mr Dung also touched on Vietnam’s defence and foreign policies, saying it will be “a friend and reliable partner to all nations, and a responsible member of the international community”. “Vietnam will not be a military ally to any country and will not allow any country to set up military bases on Vietnamese territory,” he said.

With regard to challenges to regional security, Vietnam “adheres to the principle of peaceful dispute settlement on the basis of international law”, he added.

Mr Dung also announced Vietnam’s decision to participate in United Nations peacekeeping operations, “first in such areas as military engineering, military medicine and military observation”.