"Given Iran's repeated failure to live up to its own commitments, and the need to address fundamental issues related to Iran's nuclear program, the United States and international community continue to have serious concerns," White House press secretary Robert Gibbs said in a written statement to the media.
In a deal struck with Turkey and Brazil, Iran said it would export much of its low-enriched uranium to Turkey. In return, Iran would get fuel rods of medium-enriched uranium to use in a Tehran medical research reactor. The move was seen as an attempt by Iran to prevent a looming round of United Nations sanctions.
But the nations leading the charge for more punitive action against Iran over its nuclear defiance, including the U.S., were hardly swayed.
Gibbs said that Iran still must make clear that its nuclear program is intended only for peaceful purposes "or face consequences, including sanctions."
The U.N. has already imposed three rounds of financial sanctions on Iran for its refusal to suspend uranium enrichment. The process is key to concerns over its program, because it can produce either low-enriched uranium needed to fuel a nuclear reactor or the highly enriched uranium needed to build a warhead.
Iran's decision to continue its program to enrich uranium to near 20 percent is a direction violation of existing U.N. Security Council resolutions, Gibbs said.
The White House spokesman added that the declaration issued out of Tehran is also vague about Iran's willingness to meet as promised with the set of countries working to resolve the nuclear standoff - the U.S, China, France, Russia, Britain and Germany.
An original U.N. proposal called for the Iranian uranium stockpile to be sent to Russia to be further enriched to 20 percent, then turned into fuel rods to power a Tehran medical research reactor that produces isotopes for cancer treatment. The material returned to Iran as rods cannot be processed beyond its lower, safer levels.
Questioned later in a briefing with reporters, Gibbs said the deal does nothing to change the steps, or timing, of the U.S. pursuit of international sanctions against Iran. He said Iran's proposal is less than what it agreed to last October - a deal never came to fruition.
"The words and the deeds of the Iranian leadership rarely coincide," Gibbs said.
He said Iran must submit its proposal to the International Atomic Energy Agency for formal consideration.