WASHINGTON - China's military buildup is forcing the United States to revise plans for any showdown over Taiwan, a U.S.-armed self-governing island that Beijing claims as its own, a top Pentagon official said on Thursday.

President Bill Clinton sent aircraft carriers to the region, seen as one of Asia's most dangerous hot spots, after China fired missiles near Taiwan's main ports in 1996 in an attempt to sway voters in the island's first direct presidential election.

"Today, we would calculate the operational challenges in light of new military capabilities and technologies China has acquired, just as we have always adjusted to new realities," Peter Rodman, assistant secretary of defense for international security affairs, said.

While the exact response might not be the same now, "our ability and our will to meet our security commitments remain firm," he told the congressionally created U.S.-China Economic Security and Review Commission.

China now fields "well over" 700 short-range ballistic missiles on its coast across the 100-mile (161-km) strait from Taiwan, adding about 100 missiles a year, Rodman said.

U.S. policy for decades has been to oppose any change to the cross-straits status quo by either Beijing or Taipei.

China's continuing military buildup "changes that status quo and requires us to adapt to the new situation, as we are doing," Rodman said in a written statement.

RISK

To hedge any risk, Washington is weighing deployment of bombers to Guam "on a more routine basis" as well as boosting its naval presence, James Thomas, a deputy assistant secretary of defense for resources and plans, told the commissioners.

Roger Cliff of the RAND Corporation, a nonprofit that does many studies for the Pentagon, said China is turning out weapons comparable in capability to the systems that "still make up the bulk" of those used by U.S. forces.

"If the United States is to keep its qualitative military advantage over China, therefore, we will need to continue to develop and field systems that are significantly more advanced than the types currently in our inventory," he said in written testimony.

Rodman said the upcoming 2006 edition of the Pentagon's annual report on China's military power would say Beijing's military purchases suggest it is "generating capabilities that go beyond a Taiwan scenario and are intended to address other potential regional contingencies, such as conflict over resources or territory."

China is the only major nuclear power expanding its nuclear arsenal, setting the stage for a possible renunciation of its historic "no first use" of nuclear arms doctrine, Rodman said.

"Indeed, comments from a People's Liberation Army major general last summer suggest that a debate over this longstanding declaratory policy might already be under way in China," he said.

Major General Zhu Chengdu said in July China would be prepared to strike the United States with nuclear weapons if U.S. forces stepped into a confrontation with Taiwan. His comments were disavowed by the Chinese government.