Reports in the U.S. media say Washington and its European allies have rejected Iran's latest letter on its controversial nuclear program and they now plan to seek additional UN Security Council sanctions.
The United States, Britain, France, Germany, China, and Russia plan to discuss the next step to take after receiving Iran's response to their offer of economic and technical incentives in return for halting uranium enrichment.
But "The Washington Post" and "The New York Times" say the United States has rejected the Iranian response.
White House spokesman Dana Perino says Washington and its allies want "punitive" measures against Iran because of its weak response to an international offer for freezing its nuclear program.
Perino made the remarks ahead of new talks between the United States and officials of the five other countries on the latest Iranian reaction.
According to U.S. media reports, the United States and its allies want to press for new UN Security Council sanctions. But diplomats say Russia and China could resist the move.
The one-page letter from Tehran was presented on August 5 to European Union foreign-policy chief Javier Solana, who forwarded the document to the five permanent members of the UN Security Council and Germany.
"Obviously, as we've stated before, we are looking for a clear, positive response from Iran. And in the absence of that, we are going to have no choice than to pursue further measures against them as part of our dual-track strategy," Gonzalo Gallegos, the acting deputy spokesman for the U.S. State Department, said in Washington on August 5.
Gallegos went on to describe the dual-track strategy as a "carrot and stick" approach to diplomacy, suggesting that Washington will seek further UN sanctions against Iraq if Tehran rejects the incentives package.
On August 4, Iranian Foreign Ministry spokesman Hassan Qashqavi suggested that Iran would not agree to halt enrichment activities -- instead, repeating Tehran's position that it has the right to develop nuclear energy for peaceful civilian purposes under the Nuclear Nonproliferation Treaty (NPT).
"No one can deny that enrichment in the framework of NPT is Iran's inalienable right," Qashqavi said.
Washington and its Western allies have said that if Iran's response to the incentives package was not positive, the next step would be to expand UN sanctions. The UN Security Council has imposed three rounds of penalties on Iran since 2006.
Russia and China, veto-wielding permanent members of the UN Security Council, have been reluctant to impose sanctions in the past. But they have voted for all three sanctions resolutions in the end after initial drafts were watered down.
The incentives proposal was aimed at getting preliminary talks under way before starting full negotiations. Under the plan, formal talks will not begin until Iran first freezes its uranium-enrichment program -- the part of Iran's nuclear program that most worries the West because it could allow Tehran to build nuclear weapons.
Iran, the world's fourth-largest oil producer, insists that it is only trying to develop nuclear technology in order to produce electricity. It has repeatedly refused to halt its nuclear work, saying that it has a right to develop peaceful nuclear technology for civilian purposes.