CBS/AP/ February 20, 2012, 3:21 AM

U.N. nuclear inspectors arrive in Iran

Iranian President Mahmoud Ahmadinejad, speaks at a ceremony in Iran's nuclear enrichment facility in Natanz, 300 kms 186 (miles) south of capital Tehran, Iran, Monday April, 9, 2007. Iran announced Monday that it has begun enriching uranium with 3,000 centrifuges, a dramatic expansion of a nuclear program that has drawn U.N. sanctions and condemnation from the West. President Mahmoud Ahmadinejad said at a ceremony at the enrichment facility at Natanz that Iran was now capable of enriching nuclear fuel "on an industrial scale." Asked if Iran has begun injecting uranium gas into 3,000 centrifuges for enrichment, top nuclear negotiator Ali Larijani replied, "Yes." He did not elaborate, but it was the first confirmation that Iran had installed the larger set of centrifuges after months of saying it intends to do so. / AP Photo/Hasan Sarbakhshian

TEHRAN, Iran - A team of inspectors from the U.N nuclear watchdog has arrived in Tehran for what are expected to be key talks about Iran's controversial nuclear program.

Iran's state TV says the International Atomic Energy Agency team arrived early on Monday morning. The report did not give a timetable or agenda for the two-day visit.

This is the second IAEA visit to Tehran in less than a month.

Herman Nackaerts, a senior U.N. nuclear official, said in Vienna before the team departed on Sunday that he hoped for progress in the talks but his careful choice of words suggested little expectation the meeting will be successful.

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The West suspects Iran's nuclear program is geared toward making weapons, a charge Iran denies.

The IAEA visit comes on the heels of Iran's decision to end all oil sales to France and Britain - a pre-emptive move against a European Union ban on Iranian oil imports which was set to take effect in July.

The 27-nation EU accounts for about 18 percent of Iran's oil exports, but analysts say Britain and France already have the oil supplies needed to see them through the rest of the winter, and Iran's cut-off will affect them little.

Click the player below to see CBS News correspondent Elizabeth Palmer's full report on Iran's cut-off