HANOI - President Hu Jintao on Saturday accepted Japan's invitation to visit next year, as the two countries seek to mend ties hurt by the previous Japanese prime minister's controversial trips to a war shrine.

Hu and Japanese Prime Minister Shinzo Abe talked on the sidelines of the Asia-Pacific Economic Cooperation summit in Hanoi, their second meeting since Abe took over as prime Minister two months ago.

"The invitation of the Japanese prime minister to make an official visit was accepted by President Hu and he expressed appreciation," Japan's Foreign Ministry spokesman Mitsuo Sakaba said.

"On the whole, we have a positive attitude," Chinese foreign ministry spokesman Liu Jianchao told reporters of the proposed visit.

Sakaba said the two leaders also agreed to set up a ministerial-level working group to strengthen cooperation in trade, investment, energy, science, technology and the environment.

The Chinese and Japanese leaders also agreed that top level talks should be held on conducting joint exploration for oil and gas in the East China Sea, where the two countries have competing claims.

"This is a very positive sign from the top leaders to guide officials," Sakaba said.

Six rounds of official-level talks in the past have made little progress on the issue.

Hu would be the first Chinese president and Communist Party leader to visit Japan since his predecessor Jiang Zemin did so eight years ago.

Since taking office in September, Abe has moved quickly to try to improve relations with China, which had deteriorated to their coldest in decades over visits by his predecessor, Junichiro Koizumi, to the Yasukuni war shrine.

China appeared please with Abe's overtures.

"Sino-Japanese ties are now at a crucial juncture," China's official Xinhua news agency quoted Hu as saying in the meeting.

Chinese Foreign Ministry spokesman Liu Jianchao said the leaders "agreed to keep the momentum and keep the contact between the leaders".

"This (Hanoi meeting) is a continuation of the improvement and development of relations," Liu said.

Koizumi's Yasukuni visits also strained Tokyo's relations with Seoul, but on Saturday Abe and South Korean President Roh Moo-hyun were all smiles.

"Lets strike a friendly pose," Roh said at the opening of the Japan-Korea talks as reporters shot pictures of the leaders. "We have a very close relationship as neighbouring countries, so we should show that off in the photograph too."

As they shook hands, Roh said: "Prime Minister Abe, your hands are very warm."

And Abe replied: "My heart is warm too."

China, Japan and South Korea will meet for a tripartite dialogue at the East Asia summit in the Philippines next month, Sakaba said.

Abe supported Koizumi's visits to Yasukuni, and has also paid respects there himself in the past, but has repeatedly declined to say whether he will make such visits as prime minister.

Yasukuni, where wartime leaders convicted by an Allied tribunal as Class A war criminals are honoured alongside war dead, is seen by many in Asia as a symbol of Japan's aggression in Asia before and during World War Two.

The shrine was not mentioned at Saturday's talks, Japanese officials said.

The pair also agreed to work together to try to restart stalled six-way talks on North Korea's nuclear weapons. The talks are expected to begin again next month.