The United States and European Union on Wednesday urged the United Nations' nuclear watchdog agency to report Iran to the U.N. Security Council for nuclear treaty violations, but many members of the regulatory body expressed reluctance to take that step.

In strongly worded statements to the board of governors of the International Atomic Energy Agency, the United States and several allies said Iran's years-long concealment of nuclear activities, its resumption of uranium conversion and the suspension of negotiations with Britain, France and Germany had undermined Iran's claim that its nuclear program is exclusively for peaceful purposes.

The U.S. and European governments have expressed additional dismay over statements by senior Iranian officials in the past two days that they would consider pulling out of the nuclear Non-Proliferation Treaty (NPT) and resuming uranium enrichment if their case goes to the Security Council. That body could implement punishments ranging from a verbal rebuke to economic sanctions.

"These reckless words only serve to deepen our concerns about the nature and intent of Iran's nuclear program and intentions," U.S. Ambassador Greg Schulte said during the 35-member IAEA board's closed-door meeting, according to a copy of his statement released afterward.

Canadian, Australian and Japanese officials also pressed the board to report Iran to the Security Council, diplomats said.

But the drive was running into stiff opposition from key board members, including Russia, China and a large contingent of developing countries that have nuclear programs, raising doubts over whether the matter would come to a vote this week.

"While Iran is cooperating with the IAEA, while it is not enriching uranium and observing a moratorium, while IAEA inspectors are working in the country, it would be counterproductive to report this question to the U.N. Security Council," Russian Foreign Minister Sergei Lavrov said in a speech at Stanford University, the Reuters news agency reported.

Fourteen members of the IAEA board who represent the Non-Aligned Movement, a grouping of countries dating from the Cold War, are scheduled to present their position on Thursday, IAEA officials said. Diplomats described countries in this camp as deeply conflicted: They are concerned by Iran's covert nuclear program, but at the same time feel some sympathy with Iranian assertions that big powers are trying to keep developing countries from using nuclear energy to produce cheap electricity.

In a speech to the U.N. General Assembly on Saturday, Iran's new president, Mahmoud Ahmadinejad, said his country had an "inalienable right" to produce nuclear fuel and condemned attempts by other nations to curtail its program as "nuclear apartheid."

Western officials deny such a bias. "The E.U. recognizes the inalienable right of NPT parties to develop research, production and use of nuclear energy for peaceful purposes," British envoy Peter Jenkins, speaking for the European Union, told the board.

But, he said, "Iran gives every sign of being intent on developing fissile material production capability well before the international community obtains what it needs: confidence that Iran's program is exclusively peaceful in nature."

Britain, Germany and France have been negotiating inconclusively with Iran for close to two years, offering diplomatic and economic concessions in exchange for a permanent end to elements of Iran's nuclear program that could be used to make bombs. Iran's resumption last month of several operations it had suspended led the Europeans to seek the Security Council referral.

Political analysts and diplomats here questioned whether the matter would be forwarded to the council if it faced a veto by Russia or China, or if the referral would come from a board deeply split between rich, industrialized countries, and poorer, underdeveloped countries.

Diplomats, who spoke on condition of anonymity because of the sensitivity of the matter, said intense, behind-the-scenes lobbying was underway to persuade some countries to abstain rather than vote against a referral. They were also discussing what sort of action the Security Council might take if the matter were forwarded.

The European Union has circulated a draft of a resolution that would refer Iran, a copy of which was given to The Washington Post. It cites Iran's "many failures and breaches of its obligations to comply" with Non-Proliferation Treaty requirements to notify the IAEA about its nuclear activities.

"Iran's co-operation with the Agency was marked by extensive concealment, misleading information and delays in access to nuclear material and facilities," the draft says. It states that the IAEA board is "gravely concerned" that Iran has not stopped uranium enrichment-related activities that it resumed a month ago at its Isfahan plant in central Iran.

The draft stops short of calling for sanctions, urging the Security Council instead to advise Iran to heed the IAEA's demands to "suspend all enrichment-related and reprocessing activity," return to negotiations and give IAEA inspectors greater access to nuclear facilities and personnel.

On Tuesday, Ali Larijani, secretary of Iran's Supreme National Security Council and its chief nuclear negotiator, told reporters at a news conference in Tehran that Iran might resume uranium enrichment and pull out of the Non-Proliferation Treaty if its case is forwarded to the Security Council.

In Vienna on Wednesday, a member of the Iranian delegation, Ali Azrar Sultani, told reporters that Iran was "not going to withdraw from the NPT." But he said Iran would consider resuming uranium enrichment if referred to the council.