The State Department said indignant responses from Tehran to new pressure from the International Atomic Energy Agency to come clean on its nuclear program were leading nowhere and demanded that Iran stop bucking emands for the Islamic republic to meet stated pledges to cooperate with the IAEA.
"We and others have made clear all along that Iran has obligations under its international agreements, Iran has requirements from the (IAEA) board and Iran has commitments that Iran has made itself that we and others expect Iran to live up to," spokesman Richard Boucher said.
"That's what we expect Iran to meet and threats and other posturing don't get us anywhere," he told reporters.
His comments came after Iran threatened to reconsider its cooperation with inspectors in response to a critical IAEA report and the consideration by the agency's Board of Governors of a resolution that calls for probe into its suspected nuclear weapons program to be toughened and wrapped up within months.
The conservative speaker of the Iranian parliament, Gholam Ali Hadad-Adel, warned the assembly may not ratify Iran's signature of the additional protocol to the nuclear Non-Proliferation Treaty (NPT) allowing tougher UN inspections.
And, according to press reports, Iranian President Mohammad Khatami told Britain, France and Germany in writing to ease the pressure, or risk pushing Iran to consider "other alternatives".
Iran asserts that it is only seeking to generate nuclear power to meet future energy needs, and contends that it has completely abided by its commitments to the NPT and has cooperated with the IAEA.
Iran's compliance with a string of IAEA demands was brokered last October by the three European states, who pledged that Iran could eventually hope to receive technological assistance if it managed to quash suspicions over its nuclear activities.
IAEA chief Mohamed ElBaradei said on Monday that Iran's cooperation had so far been "less than satisfactory" and that the clerical regime needed to be "proactive and fully transparent".