Efforts by south-east Asian leaders to agree a united front in their disputes with China have collapsed for a second consecutive summit, highlighting an increasingly assertive stance by Beijing.

Benigno Aquino, the president of the Philippines, dismissed a statement by Cambodia, the chair of the Association of Southeast Asian Nations and an important China ally, which said the bloc had agreed not to raise the South China Sea disputes in international forums.

“There were several views expressed yesterday on Asean unity which we did not realise would be translated into an Asean consensus,” Mr Aquino said at a meeting between Japanese and Asean leaders in Phnom Penh, the Cambodian capital, on Monday. “For the record, this was not our understanding. The Asean route is not the only route for us. As a sovereign state, it is our right to defend our national interests.”