A U.S. official said the administration was insisting on tough wording because it feared a weak message could encourage other countries that might be interested in developing nuclear weapons. "The rubber meets the road on the NPT right now," said the official, who spoke on condition that he not be identified. "People are making calculations on this, people in laboratories."
Britain, France and Germany are leading the effort to draft a more moderate resolution that would recognize Iran's past concealment but would stop short of declaring it in noncompliance.
The dispute marked a rare public disagreement between the United States and Britain. But diplomats said the European countries were concerned that language regarded as too punitive or inflammatory by Iran could end its openness to IAEA inspections and talks with the West.
The three European countries brokered a deal last month in which Iran agreed to come clean on its nuclear program, suspend its enrichment program and accept more intrusive inspections in exchange for access to nuclear technology for its civilian program.
Some smaller European countries as well as other nations represented on the board agreed with the U.S. that the language from the "Big Three" was too weak, but there was disagreement over how tough to be, diplomats said.
The board was scheduled to resume debate Wednesday.
Backroom discussions were expected over the weekend in Vienna and the capitals of the countries involved to come up with language acceptable to both sides by Wednesday. One idea gaining support is to establish a timetable for Iran's acceptance of tougher inspections and dismantling its elements of its nuclear program, several diplomats in Vienna said.
Diplomats said the United States might try to block a resolution that it considered too weak.
"No resolution is better than a bad resolution," said a senior Western diplomat. "We can take the issue up in March after the next report following the aggressive inspection process" now underway.
