The White House called on Iran to refrain from any more tests. And Secretary of State Condoleezza Rice and Defense Secretary Robert Gates said the tests were more evidence of the need for 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.
Analysts said an early assessment showed that U.S. tracking systems detected seven missile launches, including a version of Tehran's longer-range Shahab-3, which officials have said has a range of 1,250 miles.
If true, that would put several key U.S. allies within range: Pakistan, Afghanistan, Saudi Arabia, parts of Eastern Europe and Israel - Iran's number one enemy, reports CBS News Chief Foreign Affairs correspondent Lara Logan.
"It's ideally suited for attacking targets in Israel. It's got just the range you need for it," John Pike of Global Security told CBS News.
Intelligence analysts were studying data from radar, satellites and other tracking systems to determine the distance it traveled, look at its accuracy and so on, one official said.
Gates said he had not been informed whether the test showed a capability beyond what the U.S. already has seen from Iran.
Nevertheless he said: "I think this certainly addresses the doubts raised by the Russians that the Iranians won't have a longer-range ballistic missile for 10 years to 20 years.
"The fact is they've just tested a missile that has pretty extended range," Gates said.
Analysts assessed that the launches were part of what they called "troop training." That is, 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 - a "tit-for-tat" - in recent escalating threats and counter-threats 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 Gulf.
Gates said that while there is a "lot of signaling going on" with the rising rhetoric, he said he does not think the U.S. is closer to a confrontation with Tehran. And he repeated that the Bush administration strategy is to focus on "the diplomatic and economic approach to dealing with Iran," rather than using military force.
Iran says the program is for energy and the U.S. and others allege it is to develop nuclear weapons.
In Congress, 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 to a House committee. Iran has not yet perfected uranium enrichment and U.N. sanctions have hurt its ability to obtain technology for missile programs, he said.
Committee Chairman Howard Berman, a Democrat, 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."
A White House spokesman called Wednesday's tests "completely inconsistent with Iran's obligations to the world."
"They should also refrain from further missile tests if they truly seek to gain the trust of the world," Gordon Johndroe, spokesman for the National Security Council, said in Japan where President George W. Bush is attending the Group of Eight summit.
Iranian President Mahmoud Ahmadinejad, on a visit to Malaysia, told a news conference Tuesday that the U.S. and Israel were "focusing on propaganda and psychological war."
"Before, it would be considered as a serious issue," he said, speaking through an interpreter. But Iranians are so used to the threats that they now treat it as a "very funny show. ... These type of wars are considered as a funny joke."
He added, "I assure you that
But even as Ahmadinejad and other Iranian officials have dismissed the possibility of attack, Tehran has stepped up its warnings of retaliation if the Americans - or Israelis - do launch military action, including threats to hit Israel and U.S. Gulf bases with missiles and stop oil traffic through the vital Gulf region.
On Tuesday, Rice and Czech counterpart Karel Schwarzenberg signed a deal allowing the U.S. to base anti-missile defenses in the Czech Republic. The system would place radar interceptors there and missiles in Poland.
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.