Unable to bridge that rift, delegates at a board of governors' meeting of the International Atomic Energy Agency decided to adjourn until next week in hopes of finding a compromise. The break would be a chance for high-level negotiations to continue in the capitals of the 35 board members, a spokeswoman said.
The move followed a failure by IAEA delegates to reconcile U.S. wishes for strong censure of Iran's past covert nuclear activities and European hopes of encouraging Tehran's newfound openness by refraining from overtly harsh language or any formulation that would result in Security Council involvement.
Addressing delegates, U.S. Ambassador Kenneth Brill assailed Iran for 18 years of "violations and lies," including enriching uranium, processing small amounts of plutonium and other activities that Washington says point to a weapons agenda.
"Iran systematically and deliberately deceived the IAEA and the international community about these issues for year after year after year," he said. The purpose, he said, was "the pursuit of nuclear weapons."
Such conduct by Iran "constitutes noncompliance with its safeguards obligations," Brill said, in language that indirectly accused Tehran of violating the Nuclear Nonproliferation Treaty — an act that normally results in Security Council involvement.
While acknowledging that some of its enrichment centrifuges had traces of weapons-grade highly enriched uranium, Iran insists its enrichment program was low-level and only for power generation. It asserts the high-level traces were inadvertently imported on material it purchased abroad.
In comments that provoked an unusually sharp response from IAEA Director General Mohamed ElBaradei, Brill suggested a statement in ElBaradei's report on Iran should have said there was no "proof" that Iran sought nuclear weapons. Instead, it said there was no "evidence."
ElBaradei dismissed the argument as "disingenuous," according to diplomats at the meeting. "In our dictionary, 'evidence' is the same as 'proof,'" he said.
Earlier, Iran submitted a letter to the board agreeing to open its nuclear programs to pervasive spot inspections, giving up attempts to wait until it saw the text of the resolution and approved its language.
But diplomats, who spoke on condition of anonymity, said Iran continued to insist it had the right to withdraw its promise to accept such inspections if the resolution made reference to Security Council involvement or contained other language it found unacceptable.
Such a move, however, would almost guarantee a strong resolution that might even meet U.S. wishes to have Iran declared in violation of safeguard agreements — triggering possible Security Council involvement.
Iranian delegate Ali Akbar Salehi suggested the United States was isolated in the board, with Germany, France and Britain backing a softer resolution.
"We think that the American delegation — or the U.S. as a whole — is sort of a hostage to its own accusations," he told reporters. "And I think the majority of the board are looking forward to see that this … is resolved peacefully."
ElBaradei has said he wants a strongly worded report that nonetheless stops short of asking for Security Council involvement.
According to a senior diplomat, a draft discussed in Vienna would have given the board the right to call an emergency session immediately should any evidence surface that Iran was guilty of "significant failures."
The United States faced resistance at the IAEA earlier this year when it pressed for the board to refer the dispute over North Korea's nuclear program to the Security Council, for consideration of sanctions.