President Hu Jintao and other APEC leaders wave as they depart following a group photo on the final day of the summit in Vladivostok, Russia, on Sunday.

President Hu Jintao said yesterday that Japan should not make a "wrong decision" over the Diaoyu Islands during his meeting with Japanese Prime Minister Yoshihiko Noda on the sidelines of the Asia-Pacific Economic Cooperation forum in Vladivostok, Russia.

The 15-minute meeting came after weeks of tension between the neighbors.

The president urged the Japanese government on Sunday to realize the seriousness of the tension over the Diaoyu Islands and stop plans for "nationalization," saying Beijing will not recognize the "purchase" of the islands by the Japanese under any circumstances.

"China will unswervingly safeguard its sovereignty, " the president said. "Japan must realize the severity of the situation and not to make a wrong decision."

Tokyo is reported to be set to finalize plans to "nationalize" the islands, that belong to China, on Tuesday.

Hu told Noda that China-Japan ties have encountered a 'severe situation' recently over the Diaoyu Islands.

China's position on the issue has been consistent and clear, he said, adding "any action by Japan to 'buy' the Diaoyu Islands is illegal and invalid and China is firmly against it."

The determination and will of the Chinese government to defend territorial sovereignty is unswerving, the president said.

He urged Japan to "be fully aware of the seriousness of the situation and not make the wrong decision," in order to safeguard overall China-Japan relations.

It is the first encounter between the leaders of the two nations since Noda announced a plan in July to "nationalize" the islands.

The move prompted strong protests from Beijing.

Tension over the islands accelerated last month when Japan detained a group of Chinese activists who landed on one of the islands, sparking anti-Japanese protests in several Chinese cities before Japan released the activists.

Speaking to journalists after the APEC forum, Noda said he told Hu that Japan hopes to develop a mutually beneficial, strategic relationship with China and that he planned to deal with current relations from a "comprehensive perspective."

This year marks the 40th anniversary of the normalization of diplomatic ties, he added.

But, analysts said, this opportunity to boost ties has been overshadowed since Shintaro Ishihara, the right-wing Tokyo governor, unveiled plans on behalf of the prefectural government to "buy" the islands in April.

Noda, facing mounting nationalist sentiment at home and growing unpopularity over domestic policies, announced a plan in July to "nationalize" the islands.

Reports on Sept. 5 said the Japanese government reached an agreement with the so-called private owner of the islands to pay 2.05 billion yen ($26.15 million) to buy three of the five uninhabited islands.

Tokyo is expected to hold a cabinet meeting on Monday to officially affirm the final guidelines for "nationalizing" the islands, sources told Japan's leading newspaper Yomiuri Shimbun on Sept 7.

Japanese media also said the deal will be finalized on Sept. 10.

China Daily contributed to this story.