"We and other countries have expressed our concern regarding this action to the Chinese."
 
Using a ground-based medium-range ballistic missile, the test knocked out an aging Chinese weather satellite about 865km above the earth on January 11 by slamming into it, Johndroe said.
 
A senior White House official, requesting anonymity, said that Britain, Japan and South Korea were expected to express their concerns to China soon.
 
A key concern is debris that could interfere with civilian and military satellite operations on which the West increasingly relies.
   
On the day of the test, a US defense official said the United States was unable to communicate with an experimental spy satellite launched last year by the Pentagon's National Reconnaissance Office. But there was no immediate indication that this was a result of the Chinese test.
   
No such publicised destruction of a satellite in space has occurred in at least 15 years, said Marco Caceres, a space expert at the Teal Group, an aerospace consulting firm in Fairfax, Virginia.
   
No surprise

Aviation Week & Space Technology, the first to report the test, cited space sources as saying a Chinese Feng Yun 1C polar orbit weather satellite, launched in 1999, was destroyed by an antisatellite system launched from or near China's Xichang Space Centre in Sichuan Province.
   
The satellite-killing capability demonstrated by China was no surprise to the Bush administration, which revised US national space policy in October with an eye on boosting protection of US civilian and military satellites.

In a major speech about the policy last month, Robert Joseph, the state department's point man for arms control and international security, said other nations and possibly terrorist groups were "acquiring capabilities to counter, attack and defeat US space systems."
   
"No nation, no non-state actor, should be under the illusion that the United States will tolerate a denial of our right to the use of space for peaceful purposes," Joseph said on December 13.
   
Classified

In classified projects shielded from public debate, the US has been widely reported to be developing satellite-killers of its own, using more advanced technologies, including lasers.
   
Caceres said he expected the test to strengthen the Pentagon's hand in seeking funds from congress to press a host of costly military space programs, almost all of which are over budget and behind schedule.
   
"They are going to use this for as much as they can," he said, referring to Pentagon officials. Major corporate beneficiaries could be Lockheed Martin Corp., Boeing Co. and Northrop Grumman Corp., which build US communications, surveillance and early-warning satellites, Caceres added.