Washington, Aug. 1: Speaker Nancy Pelosi began a fraught tour of Asia on Sunday that administration officials say they now expect will include a stop in Taiwan, despite China’s increasingly sharp warnings in recent days that a visit to the self-governing island would provoke a response, perhaps a military one.

Ms. Pelosi arrived in Singapore on Monday, after a weekend stopover in Hawaii to consult with American commanders responsible for the Indo-Pacific. She said in a statement that she was planning to travel on with a congressional delegation for high-level meetings in Malaysia, South Korea and Japan, and did not mention Taiwan.

But it would not be unusual to omit Taiwan from an announcement given security concerns, and President Biden’s aides said she was expected to proceed with the plan for the highest-level visit by an American official to the island in 25 years. Ms. Pelosi could still change her mind about traveling to Taiwan, administration officials said, but added that seemed unlikely.

Mr. Biden’s aides said he had decided against asking Ms. Pelosi directly to cancel her trip, largely because of his respect for the independence of Congress, forged during his 36 years in the Senate. He is also clearly reluctant to back down in the face of Chinese threats, including Beijing’s warning that the United States was “playing with fire,” which followed Mr. Biden’s nearly two-and-a-half-hour conversation with President Xi Jinping of China on Thursday.

At its core, some officials said, the administration concluded after the call that the potential domestic and geostrategic risks of trying to halt the visit — including letting China dictate which American officials could visit a self-ruling democracy of 23 million people that China claims as its own — were greater than allowing Ms. Pelosi to proceed.

But they said that while they had collected some intelligence on China’s likely responses, they were not yet ready to release it publicly — and they conceded that they did not know the extent to which Chinese officials were willing to risk a confrontation.

In private, American officials have urged the Chinese government to shrug off the visit, noting that Newt Gingrich visited in 1997, when he was the House speaker, and that congressional delegations regularly visit the island to express American support for its defense. But the strategic environment of Mr. Gingrich’s trip was entirely different, and in recent years Mr. Xi has made it clear he considers reunification with Taiwan a priority.

American officials were carefully monitoring Chinese government preparations over the weekend, trying to discern Beijing’s intentions. The clearest sign they saw involved the Taiwan Strait, where provocations, testing and signaling play out weekly. The Chinese military annonced on Saturday, with less notice than usual, that it would conduct drills with live ammunition in the waters off southeastern Fujian Province, about 80 miles from Taiwan.

On Sunday, a spokesman for the Chinese air force said, without specifying dates, that the country’s fighter jets would fly around Taiwan to demonstrate its ability to defend its territory. That raised the possibility that the exercise would be timed to meet the U.S. Air Force plane that Ms. Pelosi and her delegation are taking. Their trip was part of a series of efforts to reassure the region that the United States is still committed to its “pivot” to the Indo-Pacific even while pouring tens of billions of dollars in military aid into Ukraine, to shore it up against the Russian invasion.

American officials doubt the Chinese military will interfere with Ms. Pelosi’s ability to land safely in Taiwan, betting that Beijing does not want a direct confrontation with the United States. But they say it is possible that Chinese planes will “escort” Ms. Pelosi’s plane, as a demonstration of control over the air routes.

That sets up the possibility, officials fear, of an accident — akin to the kind that happened two decades ago when a Chinese air force plane collided with, and brought down, an American spy plane, leading to an early crisis in the George W. Bush administration.

Officials say they have no reliable intelligence on what the Chinese government may be planning. But they expect that the largest reaction could come after Ms. Pelosi departs, and that it could include military maneuvers in the Taiwan Strait, cyberattacks or communications cutoffs that would demonstrate Beijing’s ability to choke off the island, which is also the world’s — and China’s — largest supplier of the most advanced semiconductors in the world.

In recent weeks, American intelligence officials have warned that China may be preparing to act against the island sooner rather than later. Intelligence analysts have concluded that China may fear that the United States’ commitment to help turn the island into a “porcupine” — armed with weaponry of the kind provided to Ukraine to fend off the Russians — may make Mr. Xi and his military think that they need to move in the next 18 months, lest they lose military advantage.

A move could involve an incident in the Strait or an effort to squeeze and isolate the island, without a full invasion. But the warning is based more on analysis, officials say, than new intelligence discoveries.

William J. Burns, the C.I.A. director, said in July that China appeared “unsettled” by Russia’s struggles in Ukraine and may conclude that it needs to develop “overwhelming” capabilities before considering any move against Taiwan.

Ms. Pelosi has a long history of protesting human rights abuses by the Chinese government during her congressional career. Thirty-one years ago she visited Tiananmen Square and unfurled a banner in memory of the hundreds of protesters who had been killed there by Chinese troops in 1989, deeply angering the Chinese leadership.

Three times since he entered office, Mr. Biden has also rattled Beijing with what could have sounded to Chinese leaders like a hardening of the American commitment to defend Taiwan — and a rejection of the carefully worded ambiguity about how much to aid Taiwan in the case of a military attack.

The most recent came in late May, when Mr. Biden surprised a gathering of Asian leaders by responding “yes” when a reporter asked if he “was willing to get involved militarily to defend Taiwan.” Mr. Biden never specified what the phrase meant in his mind, and White House officials insisted U.S. policy had not changed.

Ms. Pelosi has not confirmed whether she will visit Taiwan. But she had proposed a trip to the island this year, which was postponed because she contracted the coronavirus, and when asked recently about her travels plans, she said that it was “important for us to show support for Taiwan.”

On Sunday, Ms. Pelosi revealed some more details about her itinerary, which she had previously declined to disclose, citing security concerns. Her office said that her trip would focus on “mutual security, economic partnership and democratic governance in the Indo-Pacific region.” A posting on the website of the American Chamber of Commerce in Singapore said that Ms. Pelosi would be attending a cocktail reception hosted by the group on Monday afternoon.

Mr. Xi, China’s most authoritarian leader in decades, has pledged to pursue reunification with Taiwan, though he has not specified a timeline. Some analysts fear that he may feel pressure to show a tough stance — possibly including military action — against any perceived challenges to that pledge ahead of an important Chinese Communist Party Congress this fall, when he is expected to claim a third term as leader. But other analysts have played down the risks of military escalation, arguing that Mr. Xi would probably want to avoid unpredictability ahead of the meeting.

Mr. Biden himself has seemingly alluded to the risk of a clash with China if Ms. Pelosi visits. Asked recently by reporters about the proposed trip, he said that “the military thinks it’s not a good idea right now.” The president has also been shoring up US relations with Asian allies as a potential counterweight to China’s rise.

A spokesman for China’s Foreign Ministry, Zhao Lijian, told reporters last week that China would take “firm and resolute measures” if Ms. Pelosi visited Taiwan and that the United States would be “responsible for all of the serious consequences.” Some political analysts and state media commentators have suggested that China would activate its air force to prevent the visit — raising the specter of armed conflict.

The Biden administration insists that its stance on Taiwan has not changed, a message that Mr. Biden relayed to Mr. Xi during their phone call, according to the White House. Longstanding American policy acknowledges, without endorsing, China’s position that Taiwan is part of its territory, and holds that the United States would protect the island without saying exactly how.

But the president has little official authority over Ms. Pelosi and her travel plans. And rising anti-China sentiment in both the Democratic and Republican parties makes it awkward politically for Mr. Biden to openly discourage her trip.

Domestic politics, in both China and the United States, has left little room for graceful de-escalation, said Chen Qi, a professor of international relations at Tsinghua University in Beijing. It could cost the Democrats politically if Ms. Pelosi decides not to visit Taiwan, Professor Chen said in an interview with a journalist for Xinhua,, China’s state news agency. And China cannot afford to be seen as weak in the face of a perceived provocation.

“Now it’s up to who blinks first,” Professor Chen said.-Agencies