The leaders of China and Japan held their first formal talks on Saturday since clashing two months ago over disputed islands, in what appeared to be a hastily arranged attempt to patch up differences between the two Asian powers.

The leaders of Japan and Russia, who have also sparred recently over the Kurile Islands in the Pacific, also met Saturday, but appeared to remain divided.

The meetings took place on the sidelines of a summit meeting of 21 Asia-Pacific nations that Japan is hosting in this port city.

The 20-minute meeting between the Japanese prime minister, Naoto Kan, and the Chinese president, Hu Jintao, was announced at the last minute, and appeared to yield little of substance. However, Japanese officials called it significant that the two had met at all, after Beijing had appeared to rebuff repeated attempts by Tokyo to bring the two together for formal talks.

Ties between the neighbors, long troubled by the bitterness over Japan’s militarism in the 1930s and 1940s, hit their lowest point in years in September after Japan arrested a Chinese fishing trawler captain near disputed islands in the East China Sea, known as the Senkaku in Japanese and Diaoyu in Chinese. China responded by suspending midlevel diplomatic talks; cutting off exports of rare earth metals, which are used to make electronics; and seizing four Japanese businessmen.

Japan released the captain two weeks later, but China demanded an apology and compensation; Tokyo responded by demanding that Beijing pay for damage to a Japanese coast guard vessel that Japan said had been rammed by the Chinese trawler.

Since then, Japanese officials had been trying to arrange talks between the leaders in an effort to improve ties, but the most they could manage was two brief, informal encounters during multilateral summit meetings. Diplomatic analysts have said Beijing appeared to be taking a tough stand toward Tokyo to appease domestic public opinion within China, where the standoff incited nationalistic protests.

At the start of Saturday’s meeting, both leaders appeared stiff and mirthless, briefly shaking hands and then exchanging formal pleasantries. The mood contrasted with that of a meeting Mr. Kan held earlier with President Obama, at which Mr. Kan thanked the United States, Japan’s longtime protector, for its support during the territorial disputes with China and Russia.

While Washington remained officially neutral on China’s and Japan’s conflicting claims of sovereignty over the islands, Secretary of State Hillary Rodham Clinton said the islands came under America’s treaty obligations to defend Japan in case of attack. The statement angered China, which believes the United States’ cold-war-era security alliances in Asia are being used to contain it.

Mrs. Clinton’s comment was welcomed in Japan, where concerns about China’s rise have forced the year-old Democratic Party government to seek stronger ties with the United States and reverse its previous calls to remove an American air base from Okinawa.

“For peace and stability in this region, the presence of the United States and its military is important,” Mr. Kan told reporters after meeting Mr. Obama, “and this recognition has been shared by me and many people in the country, as well as our neighboring countries.”

Mr. Kan also met with President Dmitri A. Medvedev of Russia, whose visit this month to one of several disputed islands between northern Japan and the Russian-controlled Kurile Islands drew strong diplomatic protests from Japan.

Russian and Japanese news reports said that Mr. Kan protested the visit in his meeting with Mr. Medvedev, who retorted that the islands were Russian territory.

“The president will decide for himself which region of Russia to visit,” the Russian foreign minister, Sergey V. Lavrov, said, according to the Russian news agency RIA Novosti. “It is our territory, and that’s how it will stay. Our Japanese colleagues, I hope, will adopt a more appropriate attitude toward this.”

Japanese officials said the two sides agreed that cooperation was in both countries’ interest, and the dispute did not stop them from signing a deal to build a fertilizer factory in Russia.