The United States on Thursday called for cooler heads to prevail amid regional tensions over disputed island chains, saying it was vital for the world economy to preserve stability in Asia.

US Secretary of State Hillary Clinton held a series of meetings with Asian leaders, including talks with Chinese Foreign Minister Yang Jiechi, and then separate discussions with the foreign ministers of all countries belonging to the Association of Southeast Asian Nations (ASEAN).

The stakes are high with simmering tensions between China and Japan over disputed islands in the East China Sea, and a separate row over another archipelago in the South China Sea.

"I think it would be fair to say that all Asian leaders understand that this is the cockpit of the global economy," a senior State Department official said.

"With the United States still recovering, with Europe in a profound slowdown... it is essential that we maintain peace and stability in Asia," he added.

Tensions have escalated in the South China Sea with the Philippines and Vietnam accusing China of stepping up harassment of their fishermen and ships in a bid to exert Beijing's claims to virtually all of the strategic waterway.

ASEAN foreign ministers in July failed for the first time in the bloc's 45-year history to produce a joint communique at annual talks amid divisions over whether to stand up to China over the South China Sea row.

Brunei, which next year will serve as the ASEAN chair, is one of six nations with various claims -- some of them overlapping -- over the South China Sea, through which around half of the world's commercial cargo is transported.

Clinton has pushed for ASEAN and China to agree on a code of conduct that would manage disputes and prevent incidents at sea from escalating into full-blown conflicts.

The State Department official said ASEAN leaders had described initial talks with China as "important, informal interactions. Positive. Still early phases, but I think initially encouraging."

"The ASEANs are I think encouraged by this beginning set of interactions with China. We want it to take shape and go forward."

China is also embroiled in a dispute with Japan over an archipelago in the East China Sea that Beijing knows as the Diaoyu islands and Tokyo calls the Senkaku.

Chinese Foreign Minister Yang Jiechi late Thursday accused Japan of stealing the disputed islands as he took the bitter territorial dispute to the UN General Assembly.

"They can in no way change the historical fact that Japan stole" the Diaoyu islands, Yang said in a speech.

In Clinton's meeting earlier with her Japanese counterpart Yang, she "again urged that cooler heads prevail. That Japan and China engage in dialogue to calm the waters," another senior State Department official said.

"We believe that Japan and China have the resources, have the restraint, have the ability to work on this directly and take tensions down. And that is our message to both sides."

On Thursday, China criticized Japanese Prime Minister Yoshihiko Noda for his "obstinate persistence" after he insisted there could be no compromise with Beijing on the ownership of Diaoyu islands.

Noda had said on Wednesday that the islands were "an integral part" of Japanese territory "in the light of history and of international law."

Clinton and Yang met in a New York hotel on the sidelines of the UN General Assembly and for what a US official described as a "very full meeting."

They also talked about issues concerning the South China Seas, North Korea, human rights in China and Tibet and bilateral economic relations.

Yang met on Tuesday with his Japanese counterpart Koichiro Gemba, holding what was described as "stern talks" on the bitterly disputed islands but made no breakthrough, diplomats said.

China has been infuriated by the Japanese government's move to buy the East China Sea islands from a private owner.

Japan and China have disputed the islands for decades, but tensions flared again in recent weeks leading to street protests in Chinese cities.

Chinese government ships have sailed into waters around the disputed islands in recent days, along with vessels from Taiwan, which also claims the islands.

Disputed isles: claims by Japan and China
Tokyo (AFP) Sept 28, 2012 - China on Friday took its dispute with Japan to the United Nations, accusing Tokyo of stealing islands in the East China Sea over which the two sides have long wrangled.

Here is a brief outline of the governments' competing claims to what Japan calls Senkaku and China calls Diaoyu.

JAPAN

Tokyo says its government began surveying the islands in 1885 and found them unoccupied with "no trace of having been under the control of China".

Ten years later, on January 14 1895, the cabinet decided to erect a marker to formally incorporate the Senkaku Islands into Japanese territory, the foreign ministry says.

"Since then the Senkaku Islands have continuously remained as an integral part of the Nansei Shoto Islands which are the territory of Japan," it says.

Tokyo says the isles were not included in territory Japan renounced under the San Francisco Peace Treaty, which officially ended World War II, and that Beijing expressed no objection at the time to their exclusion.

China and Taiwan began claiming the islands after 1970, after the possibility emerged of energy reserves being found in the seabed nearby, Japan says.

It added that the islands that were nationalised on September 11 were previously owned by the Government of Japan until 1932 when a private citizen acquired them.

Japan says this month saw no more than "a nominal transfer of real property under domestic law, which is not a major change of the current situation".

As such, this purchase "should not raise any issues with other countries or region.

"There is no change in the policy to ensure a continued peaceful and stable maintenance and management of the islands over the long term."

CHINA

China's claims date back to the Ming Dynasty (1368-1644) when reference to the Diaoyu Islands appeared on maps and in a book during the reign of Yong Le (1403-1424), according to the Chinese government.

China also insists that a map published by Japan in the 1780s underlines the Chinese claim to islands.

Beijing says the dispute over the islands' sovereignty only emerged when they were ceded to Japan -- along with Taiwan -- at the end of the 1894-5 Sino-Japanese war, which China calls an "illegal" Japanese occupation.

After World War II, Tokyo relinquished its claim over Taiwan and the Penghu islands, which are located in the Taiwan Strait.

China says the Diaoyu islands were also supposed to have been returned to China but have wrongly remained in Japan's hands.

Taiwan separately claims ownership of the islands.