Updated

The Pentagon is studying Iran's latest missile test to figure out exactly what was launched and what it shows about Tehran's missile capabilities.

Defense Secretary Robert Gates says Iran's missile test bolsters the U.S. argument that Tehran is a threat. He also says it counters Russia's case against the need for a missile defense system in Europe.

Gates says the U.S. has said for some time that there is a real threat Iran could develop long-range missiles to use against Europe. He says Tehran's launch of several missiles Wednesday helps make that point.

The White House called on Iran to refrain from any more tests. And Secretary of State Condoleezza Rice said Wednesday the tests are more evidence that the world needs the U.S. missile defense system.

It will remain unclear how significant the test was until it is fully analyzed, said Defense Department officials who spoke on the condition of anonymity, because they were not authorized to talk publicly about the ongoing assessment.

An early assessment showed that U.S. tracking systems detected seven missile launches, two officials said. Pentagon intelligence assesses that the launches were part of what it calls "troop training." Officials noted that the test came during Iran's "Noble Prophet" exercise — an exercise also held twice in 2006, each time including multiple missile launches.

One defense official said it appeared to be the latest volley in recent escalating threats and counterthreats between Israel and Iran over Tehran's nuclear program. The Israeli military last month held a military exercise that some officials suggested was practice for the possibility of bombing Iranian nuclear facilities; the U.S. and allies on Tuesday ended a five-day exercise on protecting oil infrastructure in the Persian Gulf.

On Capitol Hill, Undersecretary of State William Burns said Iran is trying to foster the perception that its nuclear program is advancing.

But Iran's "real progress has been more modest," Burns said in testimony prepared for a House committee. Iran has not yet perfected enrichment and U.N. sanctions have hurt its ability to obtain technology for missile programs, he said.

Burns told the House Foreign Affairs Committee that the administration is pursuing a longtime goal of persuading Iran to change its course, using economic sanctions to "clarify the price of defiance."

Committee Chairman Howard Berman, D-Calif., said that "stopping Iran's nuclear threat is our most urgent strategic challenge."

"No one knows precisely when Iran will produce a nuclear bomb," Berman said in his opening statement. "But it will be soon."

Berman said the U.S., along with Russia, China and European allies, needs to make "an unconditional effort" to engage Iran diplomatically.

"I reject those who believe that talking is tantamount to surrender," he said.

A White House spokesman called Wednesday's tests "completely inconsistent with Iran's obligations to the world."

"The Iranian regime only furthers the isolation of the Iranian people from the international community when it engages in this sort of activity," said Gordon Johndroe, spokesman for the National Security Council.

"They should also refrain from further missile tests if they truly seek to gain the trust of the world," he added, speaking from Japan, where President Bush is attending the Group of Eight summit.

On Tuesday, Rice and Czech counterpart Karel Schwarzenberg signed a deal allowing the U.S. to base a missile defense shield in the Czech Republic.

State Department spokesman Sean McCormack told reporters that Iran "has an active missile program as is evidenced by these launches today and it underscores the importance of pursuing a number of different tracks to deal with various threats emanating from Iran."

He said a missile defense system is one way and diplomatic efforts at ending Tehran's nuclear program is another.

In Iraq on Wednesday, the No. 2 U.S. commander noted a decrease in the number of rocket and mortar attacks that can be linked to Iranian-sponsored fighters.

Lt. Gen. Lloyd Austin attributed the drop-off in recent weeks mainly to efforts by Iraqi forces to choke off radical elements of Shiite militias in the south. Austin said he didn't know whether the decrease reflects an intentional gesture by Iran.