Japan will use diplomatic channels to request that Chinese firms cease exploration for natural gas in Japan’s exclusive economic zone in the East China Sea should reports Beijing has designated construction zones be true, a top official said yesterday. China earlier this year built a natural gas production plant 5 km (3 miles) from an area that Japan considers to be its exclusive economic zone. Japan is concerned that the Chinese project might draw gas from its zone.

After repeatedly expressing concern to China, Tokyo began its own geological survey of the disputed area in July, a step criticised by China’s state media as dangerous and provocative. Trade Minister Shoichi Nakagawa told a TV news programme on Sunday that Japan had information that construction zones had been designated within Japan’s exclusive economic area.

“At this point this information is all we have,” Chief Cabinet Secretary Hiroyuki Hosoda told a news conference yesterday. “However, should it prove true that several zones for construction have been established, we are thinking that we would have to go through diplomatic routes and ask for such activities to be halted,” he added.

Hosoda also said that the boundaries of the exclusive economic zones would also have to be determined, but he was optimistic that a solution could be found. “There is no reason that our two nations shouldn’t be able to carry out such discussions and reach a positive conclusion,” he added. A Japanese Foreign Ministry spokesman said that Japan and China would meet this month to discuss the exploration of natural gas in a disputed area of the East China Sea.

“Certainly, through these consultations we would continue to ask for data on the project of extracting natural gas from under the sea bed,” Foreign Ministry spokesman Hatsuhisa Takashima said. Competition for energy resources has intensified between resource-poor Japan, which relies on imports for nearly all its oil and gas supplies, and China, which is stepping up efforts to develop resources to meet the demands of its booming economy.

The gas issue may further pressure ties between Tokyo and Beijing which, long haunted by China’s bitter memories of World War Two, have been chilled by Japanese Prime Minister Junichiro Koizumi’s visits to Yasukuni Shrine, where convicted war criminals are honoured with other war dead.

Koizumi has visited the shrine each year since taking office in 2001, most recently on New Year’s Day. China and South Korea, both victims of Japan’s wartime aggression, have condemned the visits. The prime minister, who has repeatedly said the visits are intended to pray for peace, defended his annual homage at the shrine again on Monday.

“I am aware that China is not happy about the visits (to Yasukuni),” Kyodo news agency quoted him as telling a lower house budget committee meeting. “But just because our ideas about honouring the souls of the dead differ, it is doubtful whether we should just fall in line when other countries say they are displeased,” he added.