BRUSSELS: 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 U.S., 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 U.N. 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 U.N. 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 U.N. 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 Iranians' counteroffer drew criticism in Europe and Israel.

"It's the same old tricks," Swedish Foreign Minister Carl Bildt, whose country holds told the European Union's rotating presidency, told the AP. "A back-and-forth for further talks."

Israeli Lawmaker Tzahi Hanegbi, chairman of parliament's foreign affairs and defense committee, speaking to Army Radio on Friday, said reports of Iran's resistance to the deal means, "We're back where we started."

Israeli Prime Minister Benjamin Netanyahu, speaking ahead of a meeting on Friday with White House envoy George Mitchell, said the U.N. nuclear agency's uranium proposal was "a positive step" toward keeping Iran from acquiring nuclear weapons.

The United States and its allies believe Iran is seeking nuclear arms. Tehran says its uranium activities are aimed only at producing atomic energy.

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.

British Foreign Secretary David Miliband said at the summit Thursday that he was "deeply concerned" about news of the Iranian sentencing of a British Embassy employee, Hossein Rassam.

"I've received very strong support from all my European Union colleagues, who see in this not just an attack on one diplomatic mission but on all the diplomatic missions in Tehran," he said.

A French researcher and French Embassy employee were both charged in a mass trial of those accused of fomenting unrest in postelection protests in Iran in June. Both are freed on bail, though neither can leave Iran pending a verdict.