Ministers from Japan and China agree co-operation in order to stabilise their energy security.
Japanese and Chinese energy firms have signed a series of co-operation agreements, indicating they may develop more oil and gas projects together in the future.
Six deals were made at a Japan-China energy seminar in Tokyo during Premier Wen Jiabao's visit there.
"This dialogue between Chinese and Japanese companies will create a lot of businesses opportunities, and we welcome Japanese companies to come and do business in China," said Ma Kai, head of China's National Development and Reform Commission.
The seminar, which attracted around 650 delegates from the oil and gas sectors, was the first meeting of its kind between the two countries.
"The seminar today, and joint oil and gas projects, will help raise Japanese and Chinese companies' competitiveness," said Japanese trade minister, Akira Amari.
Japan's biggest oil refiner, Nippon Oil Corporation and China National Petroleum Corporation (CNPC) signed an accord for long term co-operation in oil activities, which will include overseas oil and natural gas development. "The agreement will cover many things," said Fumiaki Watari, Nippon's chairman. "We will have to discuss specifics."
Nippon also expects to expand bilateral trade in crude oil, liquefied petroleum gas and other oil products. The deal followed shortly after Wen and Prime Minister Shinzo Abe pushed forward talks on the dispute over rights to drill in an oil and gas field in a region of the East China Sea.
Wen and Shinzo Abe said in a joint statement that China and Japan, the world's second and third largest oil users, will work closely in the energy sector and try to reduce greenhouse gas emissions.
"Japan and China will continue holding talks aiming to resolve the issue by the fall," added Amari. "We will speed up negotiations to come up with concrete measures."
Wen said he was confident co-operation between the two countries would help to increase fuel efficiency and ultimately stabilise global energy security. Amari added that energy ministers from the two countries intend to hold a policy dialogue once a year.