Japanese and Chinese officials began a two-day meeting in Tokyo on Friday on a dispute over gas exploration in the East China Sea that could further sour relations between the energy-hungry countries if left unresolved, Reuters reported. The row is one of several issues that have strained ties between the Asian neighbours. Tensions rose earlier this month after Japan said China had sent warships to the area and started producing oil or gas at one of the fields, near waters over which Japan claims rights. China said on Thursday it had put a naval reserve fleet on duty off its east coast near the disputed area, but a Chinese spokesman did not say whether the move was connected to the gas talks. Japanese officials said they hoped the talks, held after a four-month hiatus, would benefit both sides. China and Japan are the world's second- and third-largest oil consumers, respectively. "While protecting our national interests, I hope that we can reach a resolution to this problem that would be a plus for both Japan and China as soon as possible," Japanese Trade Minister Shoichi Nakagawa told reporters.