State television reported Hassan Rohani, secretary-general of the Supreme National Security Council, as saying: "We will set the next date that they can visit Iran."

Iranian officials had originally said the sudden postponement on Friday of a planned visit by inspectors from the International Atomic Energy Agency (IAEA) was due to Iran's upcoming new year holidays.

The United States called the suspension of IAEA visits "very troubling".

The IAEA's board of governors on Saturday sharply reprimanded Iran for withholding sensitive nuclear information, in a resolution that diplomats said left open the option of UN sanctions if Tehran did not cooperate.

UN resolution

In a meeting in Vienna, the IAEA's 35-nation Board of Governors stopped short of referring Tehran to the UN Security Council.

Non-aligned nations wanted to temper the Iran resolution, while western nations that insist Iran has been seeking nuclear arms were pushing for harsher language.

Iran says its nuclear programme
is entirely peaceful

While the 13-nation non-aligned group dropped most of its objections, it pushed through changed wording that effectively defers the threat of Security Council action against Iran until the board meets again in June.

Still, much of the language was critical, reflecting shared concerns by most board members about Iran's nuclear activities and its uneven record of cooperation with the IAEA.

The resolution "recognises" that the IAEA considers Iran to be cooperating with its probe. And it "welcomes" that Iran has signed an agreement opening its activities to pervasive inspection.

Iran's nuclear programme

But it "deplores" recent discoveries of uranium enrichment equipment by the inspectors and other suspicious activities not voluntarily revealed by Iran.

It also notes "with concern" that Iran and Libya appeared to have been supplied by the same black market network, and that "a number of questions", remain unresolved on technologies possessed by Iran that can be used to make nuclear weapons.

Moreover, it notes "with serious concern" that the board still does not have "the complete and final picture of Iran's past and present nuclear programme", needed by the IAEA to dispel suspicions the Islamic republic had a weapons agenda.

Meanwhile, diplomats said Iran's move to freeze inspections would be a huge obstacle to the agency's efforts to deliver a judgment by June on the nature of Tehran's nuclear past and present.

"If they really have nothing to hide, it is further against their interests" to raise questions about why it is placing their nuclear activities off limits to outside perusal, said a diplomat.