BEIJING — A spat over China's denial of port calls to U.S. naval vessels has led the Pentagon to deploy an increasing number of large ships to transit the Taiwan Strait in some of the most sensitive waters in East Asia.

While the U.S. Navy has explained the passage of at least seven ships through the Strait in the past nine days as the result of bad weather, it also conveys U.S. displeasure to China over its refusal to let Navy vessels dock in Hong Kong.

China has now refused entry to nine U.S. Navy vessels into Hong Kong harbor. On Friday, Navy officials said China denied permission to a U.S. Air Force C-17 flight that had been scheduled for a routine re-supply of the U.S. Consulate in Hong Kong.

The sudden port denials have angered Pentagon officials, and baffled U.S. policymakers puzzling over the message China seeks to send.

The most recent Navy vessel to be denied entry, the Pearl-Harbor-based USS Reuben James, had requested to use the port for New Year's holidays. That request was formally rejected Nov. 22.

China refused two U.S. minesweepers — the USS Patriot and the USS Guardian — from entering Hong Kong to escape bad weather on Nov. 21, then barred the USS Kitty Hawk and its escort ships and an accompanying nuclear-powered submarine from docking in Hong Kong for a long-scheduled Thanksgiving port call.

About 290 family members of Navy seamen had traveled to Hong Kong to be with the sailors during the Thanksgiving holiday, said Navy Lt. Cmdr. Steve Curry of the U.S. Seventh Fleet public affairs office in Yokosuka, Japan.

After China's refusal of entry, fleet commanders ordered both the minesweepers and the Kitty Hawk carrier group to move through the Taiwan Strait toward Japan.

"Due to the adverse weather and worsening sea conditions in the surrounding area, it was decided that the prudent path for safer seas was to transit the Strait," Curry said.

A Pacific Fleet spokesman in Honolulu, Jon Yoshishige, said it is "not unusual for our ships to transit the Taiwan Strait."

Yet entire aircraft carrier battle groups rarely do so. The last time that occurred was in 2002 when the USS Constellation aircraft carrier and its escort ships moved through the strait.

A guided missile cruiser and three guided missile destroyers escorted the Kitty Hawk. Curry did not explain why the USS Topeka, a nuclear-powered submarine that is part of the carrier battle group, did not move through the Strait as well.

A POTENTIAL FLASHPOINT

The Taiwan Strait, barely 100 miles wide at its narrowest, is a potential military flashpoint. Mainland China claims Taiwan as a renegade province, and says it has the right to seize control of the independently governed island with its military.

It aims more than 900 short-range ballistic missiles across the Strait.

The Strait, which bustles with ships, is barely 230 feet deep at its deepest, adding hazard to passage.

About 50 U.S. Navy ships normally make port calls each year in Hong Kong, a favored port for sailors. Why China has suddenly refused port entry is unclear.

"It's definitely meant to signal some dissatisfaction with American actions, and I think Taiwan is the main one," said Susan Shirk, a China expert at the University of California, San Diego, and a former State Department official dealing with East Asia issues.

FRICTION OVER TAIWAN

Washington agreed in September to sell 12 P-3C submarine-hunting aircraft to Taipei, and announced in mid-November that it would upgrade anti-missile batteries around Taiwan's capital.

China has decried the U.S. arms sales as a danger to its national security and has hinted that Congress' honoring of the Dalai Lama also helped trigger the problems.

A major military exercise in recent days along China's eastern seaboard is reported to have delayed scores of commercial airline flights in the region.

Yet Beijing has not explained why it canceled the port calls for the Kitty Hawk, its five escort ships, the two minesweepers and the Reuben James.

It also has appeared to zigzag in its limited statements. The White House said Wednesday that Chinese Foreign Minister Yang Jiechi told President Bush the port denials were because of a "misunderstanding," but Foreign Ministry spokesman Liu Jianchao later said such reports were not true.

Some experts said the Foreign Ministry might be out of the loop, as it appeared to be in January when a Chinese missile knocked an aging weather satellite out of the sky, drawing U.S. condemnation. The Foreign Ministry seemed unaware of the test.

"It suggests that there may be a lack of coordination (within the Chinese government)," Shirk said.

Pentagon boosts ship traffic in Taiwan Strait