Technical problems forced the Pentagon to delay a test of the controversial missile defence system the US wants to deploy to Eastern Europe.
The test was aborted on Friday after the target missile launched from Alaska failed to reach the required altitude. The missile defence system did not launch an interceptor missile, the Pentagon's Missile Defence Agency said.
The test has been rescheduled for sometime this summer, the agency said.
"The target did not reach sufficient altitude to be deemed a threat, and so the ballistic missile defence system did not engage it," Lieutenant General Henry Obering, III, head of the Missile Defence Agency, said.
Obering suggested old motors used in the target missile was likely behind the missile's failure to climb into space.
The Pentagon conducted one successful test in the last five years of the long-range system planned for Poland and the Czech Republic.
Kodiak Island off the coast of the Alaskan mainland is the site for launching the target missile. The interceptor missile would have been launched from Vandenberg Air Force Base north of Los Angeles.
The test had coincided with a congressional debate about deploying a missile defence shield of 10 interceptors to Poland and a radar site to the Czech Republic.
The US House of Representatives voted in May to slashed $160 million from a Pentagon request to begin preparatory work on the sites in Eastern Europe.
A successful test could help US President George W. Bush persuade Congress to restore the money, but a failure could harden the drive by the centre-left opposition Democrats to slow down the deployment.
The Democrats want to invest money in missile defence technologies that have proven to have more immediate value to counter short- and medium-range missiles as opposed to the long-range system.