WASHINGTON — Defense Secretary Gates said yesterday that America is prepared to share with China some of the information it has about America’s shoot-down of a spy satellite.

His comments came hours after Beijing complained the missile strike Wednesday could cause harm to security in outer space and some countries.

“We provided a lot of information … before it took place,” Mr. Gates told reporters during a visit to Hawaii. But, the secretary also said he is determined to be open about the American operation, and “we are prepared to share whatever appropriately we can.” Debris from the obliterated satellite was being tracked over the Pacific and Atlantic oceans but appeared to be too small to cause damage on Earth, General James Cartwright of the Marines, vice chairman of the Joint Chiefs of Staff, had said earlier yesterday. He told a Pentagon news conference that officials have a “high degree of confidence” that the missile launched from a Navy cruiser hit exactly where intended — destroying the toxic fuel tank that officials said could kill if it fell to a populated area on Earth.

It was an unprecedented mission for the Navy, so extraordinary that the final go-ahead to launch the missile Wednesday was reserved for Mr. Gates rather than a military commander.

The elaborate intercept plan had worried some international leaders, who suggested it was a thinly disguised attempt to test an anti-satellite weapon — one that could take out other nations’ orbiting communications and spy spacecraft.

Within hours of the reported hit, China said it was on the alert for possible harmful fallout from the shoot-down and urged Washington to promptly release data on the action.