Malaysian Prime Minister Najib Razak has distanced himself from growing territorial conflicts in Asia, telling a Japanese newspaper they should not jeopardise the "strategic importance" of his country's ties with Beijing.

"We must look at the big picture and not define relations with China on a single-issue basis but look at the broad spectrum of the relations, and recognise the strategic importance of our bilateral relationship with China," Najib told Thursday's Nikkei.

"We do not want (the territorial) issue to be an impediment to the growing ties between Malaysia and China," the Malaysian premier, on a visit to Japan, said in an interview with the business daily.

The comments come as Vietnam and the Philippines -- which along with Malaysia are members of the Association of Southeast Asian Nations (ASEAN) -- are embroiled in separate rows with China over control of parts of the South China Sea.

Tensions remain high in the region after an eruption of deadly anti-China riots in Vietnam over Beijing's controversial plans to drill for oil in contested waters.

Kuala Lumpur and Beijing have their own rival claims to parts of the South China Sea -- believed to hold vast deposits of oil and gas -- but Najib has played these down as he pursues closer ties with Malaysia's top trading partner.

Najib's government has also been trying to placate Chinese anger over the disappearance of Malaysia Airlines flight MH370, two-thirds of whose 227 passengers were from China.

On Thursday, Najib said: "We should heed the fundamental principles in which good diplomacy is a conductor... sovereign equality, respect for territorial integrity, peaceful settlement of disputes, and mutual benefits in relations."

He added that disputes over resources should be solved through "international law, and not economic and military solutions".

- 'Tremendous growth in China's power' -

Singapore's Prime Minister Lee Hsien Loong, speaking at the same forum, said Asia's future could go one of two ways.

The first -- which he characterised as "a good scenario" -- includes China's rise as "a benign power" similar to the United States and with "a stable strategic environment that will foster regional economic integration".

But "in a less benign scenario... tremendous growth in China's power can prove too much for the regional order to accommodate," Lee said.

Without regional trust "maritime disputes in the East and South China Seas (will) continue to fester (and there will be) tensions between other countries, too, arising from a result of historical issues, territorial disputes, and nationalist populism," he said.

"Nationalism is a growing force in many Asian countries.... as we have recently witnessed in anti-China protests in Vietnam.

"In Japan and (South) Korea, the history of the war continues to drive public sentiment towards each other.

"And in China, ...the country's astonishing progress has aroused strong nationalistic feelings, and in these are to claim China's rightful place in the sun after more than a century of humiliation," he said.

This kind of strife will set back Asia's economic development, he said, adding that China needed to be stitched into regional trade networks, including the ongoing talks over a mooted Trance-Pacific Partnership.

The comments came a day after Vietnamese Prime Minister Nguyen Tan Dung said China's placing of an oil rig in contested South China Sea waters had "seriously threatened peace".

Najib on Wednesday held talks with Prime Minister Shinzo Abe in Tokyo, which has its own territorial dispute with Beijing.

The two leaders agreed that any issues including in the South China Sea should be dealt with based on "international norms", according to the Japanese foreign ministry.