Sanctions should be imposed on Iran if it still refuses to comply with the UN Security Council resolution, United States representative to the organization said in Vienna yesterday.

Speaking at the IAEA meeting of the Board of Governors, U.S. Ambassador Gregory Shulte said, "Iran's refusal to suspend and its refusal to cooperate is a choice of confrontation over negotiation."

"Time has come for the Security Council to back international diplomacy with international sanctions," he said.

The quality of Iran's cooperation with the Vienna-based International Atomic Energy Agency (IAEA) has "seriously" declined.

The U.S. diplomat said that Iran loaded another batch of uranium hexafluoride into its 164-machine cascade just seven days before Aug. 31, the date the UN Security Council set as deadline for Iran's compliance with Resolution 1696.

Shulte said that such position would result in further isolation and sanctions.

The U.S. official said that "we must take further steps to persuade Iran to abandon its nuclear weapons ambitions."

"Iran must abandon its quest of nuclear weapons and fully meet its non-proliferation obligations," Shulte said, adding that the United States has worked with Europe, Russia, China and other like-minded countries to present Iran's leaders with a clear choice.

The negative choice is for Iran to maintain its present course of defiance -- violating the mandatory conditions laid out by the international community, while the positive choice is for it to cooperate and take tangible steps to assure the international community that their nuclear program is peaceful, Shulte said.

He said however, that "we do not seek to deny Iran nuclear energy, but Iran's pursuit of nuclear energy must be in conformity with Iran's commitments and international obligations."

He said that Iran has failed to comply with UN Security Council Resolution 1696, which makes suspension of enrichment-related activities no longer a voluntary confidence-building measure but mandatory, adding that Iran continues to press ahead to master enrichment in defiance of not only the Board of IAEA, but also the UN Security Council.

It's time for the Security Council to back international diplomacy with international sanctions, the U.S. ambassador said.

But he did said that sanctions will not signal an end to diplomacy, rather, they would be an essential element of diplomacy.