The USS Kitty Hawk and its escort ships were due to dock in Hong Kong for a four-day visit Wednesday until they were refused access. Hundreds of family members who had flown to Hong Kong to spend Thanksgiving with their sailors were stranded by the move.

"It's hard to put any kind of positive spin on this," Adm. Timothy Keating told The Associated Press in a telephone interview from his airplane on his way home from visiting U.S. and coalition troops in Iraq.

China later reversed its decision and said the ships could enter on humanitarian grounds, but the notice came while the vessels were already on their way back to their home ports. The vessels chose not to turn around.

It was the second instance in a week of China refusing to let U.S. Navy ships into the port.

Keating said two U.S. minesweepers seeking to refuel and looking for shelter from bad weather in the South China Sea had asked for permission to enter Hong Kong three or four days before the Kitty Hawk incident. But these ships also were denied, he said.

The developments come as the U.S. military has been trying to increase personal ties with the Chinese military to prevent misunderstandings and the potential for miscalculation.

Chinese warships visited U.S. naval bases in Pearl Harbor and San Diego last year, and the two navies have since held basic search-and-rescue exercises together.

High-level commanders have traveled back and forth between the two Pacific powers, while Defense Secretary Robert Gates visited Beijing earlier this month.

Asked if the refusal to let the Kitty Hawk into Hong Kong would hurt the U.S.-China military relationship, Keating said: "We'll keep working it of course, but it is difficult for me to characterize this in a positive light."

The admiral said he would to talk to officials at the State Department and the Pentagon to determine how to respond.

Keating, who heads the U.S. Pacific Command from its Hawai'i headquarters, said he was unaware of any reason for China's decision.

"It's my understanding the Chinese just said 'no,'" he said.

China has in the past barred U.S. Navy ships from Hong Kong when bilateral relations have been strained.

In recent weeks, the two sides have had disagreements over trade, Iran's nuclear program and Congress's awarding a medal to the Dalai Lama, the Tibetan spiritual leader whom China's Communist government considers an enemy.

Hong Kong has long been a favored port of call for the U.S. military, but Beijing's approval has been required since July 1, 1997, when Britain handed the former colony back to China.

The 46-year-old USS Kitty Hawk, which is home-ported in the Japanese port city of Yokosuka, is the only U.S. aircraft carrier permanently deployed abroad.