Chinese Leader and Obama in Surprise Meeting at Summit

ABOARD AIR FORCE ONE — President Obama and Prime Minister Wen Jiabao of China held an unscheduled meeting on Saturday at the end of an Asian forum to discuss economic issues and China’s festering disputes with neighbors over islands in the South China Sea, American officials said.

The encounter at the larger meeting in Bali, Indonesia, capped a week in which the administration startled Chinese leaders with what appeared to be a campaign to make clear that the United States was re-engaging in the region and not willing to cede influence in Asia to a rising China.

Besides announcing that the United States would station 2,500 Marines in Australia, the administration said that it would enhance military ties with the Philippines and send Secretary of State Hillary Rodham Clinton to Myanmar after years of mostly shunning its leadership.

Whether the session on Saturday closed gaps between the United States and China on currency matters was unclear. The United States and other Western nations have complained that China’s currency has been artificially undervalued, giving Chinese exporters an unfair price advantage. The South China Sea dispute the two men spoke of has become a focal point of discontent among China’s neighbors and provided a way for the United States to show its commitment to the region. The United States has waded into the conflict in recent months saying it was willing to mediate disputes between smaller countries and China. That was met by bitterness in China, where leaders saw it as interference.

As China’s wealth has grown, the country has made increasingly assertive claims about what parts of the sea it controls, challenging claims staked by countries like Vietnam, the Philippines and Malaysia.

A senior administration official who briefed reporters on Air Force One, said that President Obama had spoken about the dispute during the one-on-one meeting, but that China had also been forced to confront the issue during a final summit meeting with Asian leaders.

The official, who spoke on the condition of anonymity, said that of the nearly 20 leaders at the meeting, 16 voiced concerns about the South China Sea.

He said Mr. Wen at first seemed “maybe a little bit grouchy” about the confrontation, but then made statements that appeared to be less confrontational than in the past. What was interesting, the official said, was not what Mr. Wen said, but what he did not.

The official, for instance, said Mr. Wen did not say, as officials had in the past, that the disputes should be resolved bilaterally, meaning that China would take on its neighbors only one at a time, giving it an advantage because of its size and power. China has consistently balked at anything but bilateral talks, and it was not clear that Mr. Wen was indicating a change in position.

On Friday, Mr. Wen had pushed back against the United States on this issue, saying that “outside forces should not, under any pretext” interfere in a regional fight over the control of the sea.