Talks between China and Japan over sea demarcation in the East China Sea on Monday were constructive, said China's Foreign Ministry.

The talks in Beijing were meaningful and both sides showed sincerity and a constructive attitude, ministry spokeswoman Zhang Qiyue said Tuesday in Beijing.

"We hold that a fair solution to the issue should be sought through negotiations based on the United Nations (UN) Law of the Sea Convention," Zhang said.

Japan has unilaterally demarcated a controversial exclusive economic zone along the median line. It holds that the line is determined by the two countries' coastlines.

However, China holds the line is determined by the continental shelf on China's side, over which China claims exclusive rights.

Both China and Japan have a right to claim 200 sea miles of water according to international law. However, the width of the East China Sea is less than 400 sea miles and the claims of the two sides overlapped and raised disputes.

Zhang reiterated at Tuesday's news briefing that China's oil and gas exploration efforts in the East China Sea are being carried out in China's indisputable coastal waters and are a matter within the scope of China's sovereignty.