WASHINGTON (Reuters) - Iran's attempted satellite launch was a failure that fell far short of claimed successes, U.S. security officials said on Tuesday, but an analyst said the test still marked progress toward a potential weapon.

"The attempted launch failed," a U.S. intelligence official told Reuters, speaking on condition of anonymity.

"The vehicle failed shortly after liftoff and in no way reached its intended position," the official said. "It could be characterized as a dramatic failure."

A U.S. defense official gave a similar characterization of the test as unsuccessful.

But Charles Vick, a senior analyst for GlobalSecurity.org research group, said Iran appeared to have succeeded in igniting the second stage of its booster rocket and gained data that will help it perfect its launch system. The technology could also be used to develop a rocket capable of carrying nuclear weapons that could strike Europe or China, he said.

He based his assessments of the test on photographs, public reporting and earlier analyses.

"They're not there yet and that's to be expected but this is a step forward that has implications strategically," Vick said.