Iran has accused the US of planning to invade after the United Nations set a deadline for the Islamic Republic to prove it has no secret atomic weapons programme.
Following intense American pressure for action against Iran, the 35-nation governing board of the International Atomic Energy Agency (IAEA) passed a resolution setting the deadline.
Iran'sdelegation walked out of the closed-door meeting in protest, accusing Washington of having new invasion plans after Iraq.
The toughly worded resolution gives Iran - branded by the United States last year as part of an "axis of evil" with pre-war Iraq and North Korea - one last chance to prove it hasbeen complying with the Nuclear Non-Proliferation Treaty (NPT).
The United States claims Tehran has violated the treaty in its effort to develop atomic weapons secretly. Iran, which denies the allegation, could face economic sanctions if reported to theUN Security Council for breach of its NPT obligations.
"We will have no choice but to have a deep review of ourexisting level and extent of engagement with the agency vis avis this resolution," said Iran's ambassador to the UN inVienna, Ali Akbar Salehi.
His comments were in a written statement he distributed toreporters as he left the IAEA boardroom just before theresolution was passed.
US Ambassador Kenneth Brill warned that any decision byIran to suspend the IAEA inspection process would be interpretedas an admission that they were pursuing atomic weapons.
"If they wish to disrupt that (inspection) process, it canonly lead the board and indeed the international community toconclude that in fact they are not pursuing a peacefulprogramme," Brill told reporters.
In Washington, a US official said: "This time wehope there's not going to be a way to escape because thisresolution is really tightening the noose on them."
IAEA chief Mohamed ElBaradei told reporters he hoped Iranwould not end cooperation with the agency but increase it.
He said the resolution sent "a very powerful message to Iranthat they need to cooperate fully and immediately and to showcomplete transparency."
Iranian Ambassador Salehi insisted that Iran "is a ferventsubscriber to the NPT, a loyal party to it and a staunchpromoter of the Middle East as a nuclear free zone."
After the US-led war on Iraq, Salehi said that it wasclear the administration of US President George W. Bush"entertains the idea of invasion of yet another territory, asthey aim to re-engineer and reshape the entire Middle East."
Attacking Israel, Salehi said: "Among those who have pursuedand produced nuclear weapons outside The Five (official nuclearweapons states), Israel gets way with murder. It is pamperedinstead of being chastised."
Israel, like India and Pakistan, has never signed the NPT.It has also never acknowledged having nuclear weapons, thoughnon-proliferation experts say no one doubts Israel has them.