Washington: The US cannot verify reports about recent advances in Iran's nuclear programme, US State Secretary of State Condoleezza Rice said.

At a news conference with Germany's Foreign Minister Frank-Walter Steinmeier, Rice said she could not verify "one way or another" the statement by Iranian President Mahmoud Ahmadinejad that his country had started to install 6,000 'ordinary' uranium enrichment centrifuges at its underground facility in Natanz.

She said the US made its conclusions on Iran relying on the information provided by the UN nuclear watchdog, the IAEA (International Atomic Energy Agency).

According to the international organisation, Iran currently uses around 3,000 'P-1' centrifuges, which are prone to break down when working at high speed for long periods.

Iranian authorities have repeatedly said the country needs 50,000 centrifuges to provide its annual requirements for nuclear fuel.

She said the US is currently expecting Iran's reaction on the UN Security Council resolution, imposing additional sanctions on Iran, adopted in late February and expected to come into force when a 90-day deadline expires.

"We will always continue to consider refreshing both tracks but this is not the time, I think, to expect major changes," Rice told reporters.

"We have just passed a Security Council resolution and we will see how Iran responds."

Steinmeier said European nations were considering additional sanctions to be imposed on Iran. Tehran has repeatedly rejected international demands to halt uranium enrichment, insisting it needs the process to generate electricity.

Source : IANS