Noda and Manmohan Singh were to meet in Tokyo Nov 18 for their annual bilateral meet, which was cancelled following domestic developments in Japan. Prime Minister Noda last week announced dissolution of parliament and new elections have been called Dec 16.
However, Japan and India inked two agreements last week - on joint production of rare earth minerals and a social security agreement.
The prime minister and the Sultan of Brunei discussed possibilities of expanding energy cooperation, said an official.
In a photo-op Monday night, a smiling posed along with US President Obama, South Korean President Lee Myung-Bak, Chinese Premier Wen Jiabao, Australia's Julia Gillard and Cambodian Prime Minister Hun Sen.
All the leaders were attired in Cambodian traditional silk shirts, with Manmohan Singh wearing one of light orange hue. He is flanked by Australia's Gillard and South Korea's Lee.
The photo-op was ahead of a grand gala dinner Monday night.
The East Asian leaders are holding a summit here Tuesday, and are expected to announce launch of negotiations for the Regional Comprehensive Economic Partnership agreement.