Russian officials have assured their U.S. counterparts this month that they would not complete the sale of a powerful air defense system known as the S-300 to Iran.
Speaking Tuesday to the Senate Foreign Relations Committee, William Burns, undersecretary of state for political affairs, said the Russians had made assurances they would not complete the sale.
“Russia, for example, has confirmed to us that it will not deliver the S-300 system in accordance with the U.N. sanctions,” Mr. Burns said.
The new U.N. Security Council resolution 1923, which sanctions Iran for its nuclear program, includes a loophole that would allow the Russians to sell the air defense system.
In the last three weeks, Russian military leaders and diplomats have asserted both that they can complete the sale of the S-300, but that they will not complete the sale for now, as it would violate the spirit of the new U.N. sanctions.
The air defense system has been in development for a decade by the Russians.
If successfully installed in Iran, it could rebuff U.S. or Israeli aircraft that would attempt to strike Iran’s enrichment facilities in Natanz, Qom, Tehran and other cities.
On the other hand, if the air defense system failed to repel an air strike, the next-generation Russian system would be exposed as ineffective against the West’s best aircraft.
During the hearing, Mr. Burns also warned that Iranian proliferation could spark a regional arms race.
“The dangers of stimulating a regional nuclear arms race is quite serious and it is one of the concerns that animates our efforts to prevent Iran from getting nuclear weapons,” he said.