-- Setting out on a second term, President Chen Shui-bian pledged Thursday to hold off on formal independence for Taiwan but clung to his vision of a society that is basically different and perhaps permanently separate from mainland China.

Chen's inaugural address, delivered under a tropical downpour, heeded warnings from the Bush administration not to announce any plans for his next four years in office that would move this self-governing island of 23 million people closer to independence. He declared a willingness to postpone such steps, and while not renouncing independence permanently, held out the promise of several more crisis-free years in the Taiwan Strait.

In Washington, the Bush administration said it was gratified by the tone of Chen's speech, calling it "responsible and constructive."

"By making clear his administration's commitment not to take steps that would unilaterally change the status quo, underscoring its openness to seeking accord with Beijing, and reaffirming previous commitments on cross-strait relations, Chen Shui-bian's address creates an opportunity for Taipei and Beijing to restore dialogue across the strait," Scott McClellan, the White House press secretary, said.

Su Chi, who ran Taiwan's Mainland Affairs Council under the former Nationalist Party president, Lee Teng-hui, described Chen's speech as "basically tailored for the U.S." He added: "This may get the U.S. off the hook. At least, the U.S. hopes so."

Beijing has warned it will prevent Taiwanese independence at any cost, including war; in its view, the island is a province of China that must reunite with the mainland. With the United States committed to defending Taiwan, the standoff between Beijing's resolve and Chen's aspiration carries the seeds of a clash between U.S. and Chinese forces that both sides seek to avoid.

With Chen's inaugural address billed as a look at his second-term intentions, U.S. officials made it clear in recent weeks that this was not the time to test China's will, according to Taiwanese and U.S. officials. Joseph Wu, who has been assigned to head Chen's new Mainland Affairs Council, told reporters here that the president and his aides in the Democratic Progressive Party had received the message loud and clear.

Chen's second mandate also has been hampered by his thin margin of victory in the March 20 elections and a Nationalist legal challenge to the vote count that is still before the courts. As he was inaugurated, Nationalist demonstrators rallied at the edge of the crowd, and a giant sign reading "No truth, No president" hung from Nationalist headquarters facing the presidential podium.

At the same time, Chen, 53, once again rejected the "one China" principle that the government in Beijing regards as the foundation for any exchanges with Taiwan. The United States also has followed a "one China" policy since it established formal diplomatic relations with Beijing in 1979. But Chen, in much-remarked words that he refrained from repeating Thursday, has suggested that times have changed and that now there is one country on each side of the 100-mile Taiwan Strait.

"We can understand why the government on the other side of the strait, in light of historical complexities and ethnic sentiments, cannot relinquish the insistence on the 'one China' principle," Chen said. "By the same token, the Beijing authorities must understand the deep conviction held by the people of Taiwan to strive for democracy, to love peace, to pursue their dreams free from threat and to embrace progress.

"But if the other side is unable to comprehend that this honest and simple wish represents the aspiration of Taiwan's 23 million people," he continued, "if it continues to threaten Taiwan with military force, if it persists in isolating Taiwan diplomatically, if it keeps up irrational efforts to blockade Taiwan's rightful participation in the international arena, this will only serve to drive the hearts of the Taiwanese people further away and widen the divide in the strait."

Chen announced he would move ahead with constitutional reforms that Chinese authorities have defined as steppingstones to a declaration of independence. However, Chen defined the goal as streamlining the government. He specifically ruled out changing the most sensitive parts of the document, those that would affect Taiwan's international status.

"I am fully aware that consensus has yet to be reached on issues related to national sovereignty, territory and the subject of unification-independence," he said as raindrops bouncing off the podium splattered his dark suit and made his forehead glisten. "Therefore, let me explicitly propose that these particular issues be excluded from the present constitutional re-engineering project."

The Chinese government, which had no immediate reaction, said Monday that Chen is launched on a "dangerous lurch toward independence" that threatens peace in the Taiwan Strait. It was not clear, therefore, what reception Chen's offer to limit the constitutional reforms would receive in Beijing. But in the wake of Monday's statement, the atmosphere was not welcoming.

"He may have adjusted his tactics and eased his rhetoric, but we know the U.S. was very concerned about the speech and he was under pressure," said Zhu Weidong, senior Taiwan analyst at the Chinese Academy of Social Sciences in Beijing. "How far he will adjust his tactics and whether he will do what he says are still not clear."

Beyond the specific steps that may be taken in the next four years, Chen outlined a vision of the future that understands Taiwan and its democratic system to be different -- maybe irreconcilably -- from China. The mainland has to understand, he said, that Taiwan's voters ultimately will decide future relations with China. "If both sides are willing, on the basis of goodwill, to create an environment engendered upon peaceful development and freedom of choice, then in the future the Republic of China and the People's Republic of China -- or Taiwan and China -- can seek to establish relations in any form whatsoever," he said. "We would not exclude any possibility, so long as there is the consent of the 23 million people of Taiwan."

Correspondent Philip P. Pan in Beijing and staff writer Glenn Kessler in Washington contributed to this report.

A dragon-shaped balloon passes over the soaked crowd that gathered for Chen's inauguration ceremony in Taipei.Taiwanese President Chen Shui-bian said any proposed constitutional reforms would not involve issues related to the island's independence.