It was too soon to tell if the fuel tank had been shattered in the operation over the Pacific Ocean, the Pentagon said in a statement, but a senior military source said initial indications suggested that goal had been achieved.
Washington says its aim is to prevent harm to humans from the satellite's tank of hazardous hydrazine fuel. Russia and China have expressed concern, with Moscow suggesting the operation could be used as cover to test a new space weapon.
The SM-3 missile was fired from the USS Lake Erie in the Pacific at about 10:26 p.m. EST (3:26 a.m. British time Thursday), the Pentagon said in a statement.
"A network of land, air, sea and space-based sensors confirms that the U.S. military intercepted a non-functioning National Reconnaissance Office satellite which was in its final orbits before entering the earth's atmosphere," it said.
"Confirmation that the fuel tank has been fragmented should be available within 24 hours," the statement said.
The senior military source said the missile hit the satellite about three minutes after launch.
"There's a good indication that the fuel tank was hit because there was an explosion," said the source, speaking on condition of anonymity.
A Chinese state newspaper on Thursday - Wednesday in the United States - accused Washington of hypocrisy for criticizing other countries' space ambitions while rejecting a treaty proposed by China and Russia to ban weapons in space and firing a missile at the spy satellite.
China said it was monitoring Washington's destruction of the satellite.
"The Chinese side is continuing to closely follow the U.S. action which may influence the security of outer space and may harm other countries," Foreign Ministry spokesman Liu Jianchao told a regular news conference.
JUSTIFICATION QUESTIONED
