The Chinese military failed to provide the technical support requested by a team of American technicians on their second day of inspecting a grounded U.S. Navy spy plane, a Pentagon official said Thursday.

As a result, the American civilian technicians were not able to power up the aircraft to check its electronics, hydraulics and other elements, the official said, speaking on condition of anonymity.

The plane has been at a military airfield on Hainan island in the South China Sea since it made an emergency landing there April 1 after colliding with a Chinese fighter jet. The American crew was held on Hainan for 11 days before being released.

Because they were unable to complete their inspection Thursday, the American technicians planned to resume their work Friday, the official said. During Thursday's visit to the EP-3E Aries II surveillance plane, the Americans managed to take photographs of its damaged exterior.

The official said the Americans had made clear in advance that they needed certain technical support from the Chinese military in order to power up the aircraft, but for unexplained reasons that support was not provided.

It was not immediately clear whether the obstacles were China's response to Defense Secretary Donald H. Rumsfeld's decision to downgrade U.S. military relations with China.

Word of Rumsfeld's decision became public late Wednesday afternoon in Washington, which was early Thursday morning in China. The Pentagon initially stated that Rumsfeld had ordered a suspension of military contacts with China, but it later retracted that as an internal Pentagon misunderstanding. Instead, Rumsfeld ordered that all future military-to-military contacts be reviewed and approved in advance by him or his aides.

The examination of the Navy plane on Hainan island began Wednesday.

A spokesman for the U.S. Pacific Command in Hawaii, which is responsible for U.S. military operations in Asia, said there was no indication that China had responded to Rumsfeld's decision by suspending or changing conditions for the examination.

"The situation is unchanged. The technicians are still doing their assessments, and expect to be there a while," Marine Corps Maj. Sean Gibson said.

The aircraft made an emergency landing on Hainan after a collision with the Chinese fighter in international airspace.

The technicians from Lockheed Martin Corp., maker of the EP-3E, spent about four hours aboard it on Wednesday, Pentagon spokesman Bryan Whitman said in Washington.

Rumsfeld said it wasn't clear whether the plane would be flown home or partially disassembled and returned by ship or air.

Asked whether China had refused to allow the plane to be flown out, Rumsfeld repeated, "There's nothing conclusive on that point."

Chinese authorities held the 24-member air crew for 11 days while demanding that Washington take the blame for the collision. The confrontation sent ties to their lowest point since U.S. warplanes inadvertently bombed the Chinese Embassy in Yugoslavia two years ago.

Accounts from both sides indicate the plane lost its nose cone, and at least one of its four propeller engines was damaged. The impact pushed the plane into an 8,000-foot dive before the pilot regained control.

The Chinese fighter apparently broke in half, killing pilot Wang Wei.

Rumsfeld's order to review military ties came after the Pentagon on Wednesday released, then withdrew, a memo saying it was suspending such ties.

The Pentagon had previously said it was going to reconsider how to proceed with contacts. It said there were none planned this month.