The United States Friday congratulated Taiwanese President Chen Shui-bian after he was declared the winner of last Saturday's disputed election on the island. The Bush administration urged calm as the expected legal challenges of the vote-count go forward.

U.S. officials are appealing for restraint and calm in Taiwan as the election dispute plays out in the courts, while downplaying a statement by China that it would not stand idly by if election related-violence on the island spun out of control.

In a written statement, White House spokesman Scott McClellan noted that the Taiwanese Central Election Commission had officially proclaimed Mr. Chen the winner of the hotly contested election, and said the United States congratulates him on the victory.

Acknowledging pending court challenges to the election results, Mr. McClellan said the Bush administration applauds the people of Taiwan for embracing established legal mechanisms for resolving their differences and said it rejects calls for violence, which he said threaten the democratic principles to which both the American and Taiwanese people are committed.

There were similar comments here from State Department spokesman Richard Boucher, who said while election-related demonstrations in Taiwan reflect the island's vibrant democracy, the outbursts of violence seen in Taipei are to be condemned.

"On the issue of demonstrating and expressing their views, obviously we're in support of people expressing their views," he said. "On the other hand, we're against violence and we caution all sides to try to maintain peace and a calm atmosphere and let the legal procedures play themselves out. But certainly we never have a problem with people expressing their views."

China responded to the developments in Taiwan with a statement by the official Xinhua news agency warning that post-election violence there could threaten regional stability, and asserting that China "would not stand idly by" if the political crisis in Taiwan worsened.

Neither the White House nor the State Department had any direct reaction. But Mr. McClellan's written statement said the maintenance of peace and stability in the Taiwan Strait, and the welfare of the Taiwanese people "remain of profound importance" to the United States.

He said to advance those goals, the United States will fulfill its obligations under the 1979 Taiwan Relations Act by Congress, which among other things commits the United States to meet Taiwan's needs for defensive arms.

Mr. McClellan said it falls to both Taiwan and Beijing to work for peace and stability by "pursuing dialogue through all available means" and by "refraining from unilateral steps that would alter Taiwan's status."

A senior diplomat who spoke to reporters here cautioned against over-reacting to the Chinese statement, which he said did not appear "to be all that belligerent." He said the United States stands up for democracy and legal system of Taiwan and said in his words "everybody ought to respect that."