EU says Iran must stick by uranium limitation deal

European leaders pressed Iran Friday to stick by a deal that would limit its uranium enrichment, voicing "grave concern" over the country's nuclear program.

Western diplomats said this week that Tehran had rejected a plan proposed by International Atomic Energy Agency chief Mohamed ElBaradei at talks involving Iran, the US, Russia and France.

The plan calls for Iran to export most of its enriched uranium, offering instead to enrich it to a higher level inside the country under UN supervision. Iran missed an initial deadline of last Friday to respond, and instead this week offered to enrich its uranium to a higher level inside the country under UN supervision.

EU leaders expressed "grave concern over the development of Iran's nuclear program, and Iran's persistent failure to meet its international obligations," according to a draft statement circulating on the second day of a two-day EU summit in Brussels.

The statement urged Iran to agree to the UN atomic watchdog's proposal for supplying nuclear fuel to Tehran's research reactor, saying such an agreement "would contribute to building confidence." A copy of the statement was obtained by The Associated Press.

The EU leaders said progress on the nuclear issue "would pave the way for enhanced relations between the EU and Iran ... in the political, economic, security and technical fields."

EU leaders also said they deplored continued violations of human rights in Iran, and urged the authorities to release EU citizens and employees of European missions there.

Meanwhile, US Secretary of State Hillary Clinton signaled on Friday that the United States will allow talks with Iran over its nuclear program to play out before considering fresh sanctions against Tehran.

Asked during a CNN interview whether it was time to stop talking with Iran and move toward sanctions, Clinton said: "We are working with the IAEA, with France, Russia ... who are all united and showing resolve in responding to the Iranian response and seeking clarification. So I'm going to let this process play out."

Clinton did not say under what conditions the United States would consider fresh sanctions against Iran.

Reuters contributed to this report