Iran insisted Sunday that it remained committed to an agreement allowing unfettered inspection of its nuclear facilities but gave no date for when it will sign the deal, despite mounting Western pressure.

Mohamed ElBaradei, director-general of the International Atomic Energy Agency, said last week he expected Iran to sign a protocol to the Nuclear Non-Proliferation Treaty "shortly."

A Western diplomat in Vienna, where the IAEA is based, suggested Tehran was stalling, and said the United States and other countries were impatient "for Iran to keep its promises and sign."

"From our point of view, it's definite. We have announced to the IAEA that we have agreed to sign," Foreign Ministry spokesman Hamid Reza Asefi told reporters at a weekly press conference.

Asefi refused to set a date for Iran's signature but said the government was studying the matter.

"The matter is now under study at the Cabinet. After the initial signature and finalization of the issue, it will be handed over to the Parliament," the spokesman said.

Under Iran's constitution, any international agreements have to be approved by Parliament and ratified by a hard-line constitutional watchdog, the Guardian Council.

Iran agreed last month to open suspect nuclear sites that had been off-limits and to let inspectors from the IAEA, the U.N. nuclear agency, to conduct unannounced checks to insure the country is not trying to develop atomic weaponry, as alleged by Washington.

The 35-member board of the Vienna-based IAEA last month adopted a resolution that censured Iran for 18 years of secrecy of its nuclear program and warned it to stay in line with international efforts to ensure the country has no nuclear weapons ambitions.

The resolution did not confront Iran with a direct threat of U.N. Security Council sanctions as Washington wanted, but it warned Tehran that the IAEA would consider additional action if "further serious Iranian failures" were found.

Iran insists that its atomic energy program is peaceful and geared only toward energy production.

Under international pressure, Iran suspended uranium enrichment Nov. 9, but Asefi insisted that the decision was voluntary and temporary. He said enrichment would be renewed to create fuel for power plants, saying "Iran won't give up its legitimate rights for (the) peaceful use of nuclear energy."

The United States has been pushing the IAEA to force Iran to permanently halt uranium enrichment.