By Susan Cornwell
Eric Edelman, the Pentagon's undersecretary for policy, was responding to questions at a Senate hearing about reports that Iran would soon acquire an advanced Russian anti-aircraft missile system.
"To the best of my knowledge, I don't believe we think the missiles referred to … are in fact slated for delivery by the end of this year," Edelman told the Senate Armed Services Committee.
"But it is something that we are watching very closely," he said. "It is a very serious capability that would be a concern to us as well as others in the region."
Western and Israeli experts have said that if Tehran acquired the S-300 missile batteries, it would make any strike by Israel or the United States on Iran's nuclear sites tougher. The system is also known in the West as the SA-20.
The United States and others accuse Iran of seeking to build nuclear weapons under cover of its nuclear energy program. Tehran rejects the charge.
The nuclear dispute and hostile rhetoric have fed speculation especially in global financial markets that the risk of a confrontation between Iran and the United States or Israel was growing.
The United States and Israel have not ruled out military action if diplomacy fails to resolve the dispute.
There have been conflicting reports about whether Iran was buying the S-300 system.
Iran's Defence Minister Mostafa Mohammad Najjar said last year Russia had agreed to deliver the missiles to Iran under a signed contract. But Iran's foreign ministry denied earlier this month that Iran had bought the system.
"Unfortunately, Russia has provided a lot of conventional military support to Iran. In general, I don't think that has been as helpful as … some of their diplomatic efforts have been," Edelman said.
At the same hearing, Assistant Secretary of State Dan Fried said that Russia had been a constructive partner in diplomatic efforts — unsuccessful so far — to pressure Iran to suspend its nuclear enrichment program.
Fried said the United States hoped to continue this work with Russia despite tensions over its war with Georgia. But, he said, Washington would not give up its support for Georgia's territorial integrity in order to keep Moscow working on the Iranian nuclear challenge.
"It's certainly seems to be in Russia's interest to work with us, because a nuclear armed Iran would be a threat to them," Fried said.
"We are going to try to work with the Russians in areas where we have common interests," he said, but added, "I cannot imagine circumstances where we would bargain away the rights of sovereign countries for the privilege of working with the Russians in areas of common interest."
(Editing by Kristin Roberts and Jackie Frank)
