Singaporean Foreign Minister Vivian Balakrishnan called for enhanced cooperation between Southeast Asian states and Japan to maintain the rule of law at sea amid China's rising assertiveness in the South China Sea.

"Japan and other regional stakeholders need to work together with ASEAN to advance regional peace, stability and prosperity and to uphold and protect rules-based regional and international orders," Balakrishnan said Tuesday in a speech in Tokyo, referring to the 10-member Association of Southeast Asian Nations, of which Singapore is a member.

Although Japan and Singapore are non-claimant countries in the territorial disputes involving China in the South China Sea, the busy sea lane stretching from the Strait of Malacca to the South China Sea is of key interest for the two maritime nations.