U.S. Secretary of State Condoleezza Rice says Iran has repeatedly avoided answering questions about its nuclear program and lied to United Nations inspectors.

Speaking before arriving in Moscow, Rice said Iran has deliberately deceived International Atomic Energy Agency (IAEA) officials. 

On Thursday, Iran and the U.N. nuclear agency wrapped up three days of talks on Tehran's nuclear program.  Iran's deputy nuclear negotiator Javad Vaeedi said talks will continue next week.

Iran and the IAEA agreed in August on a timetable for Tehran to answer questions about its nuclear program by December.  But the agreement does not require Iran to suspend the current expansion of its uranium enrichment facilities.

This week's meetings focused on centrifuges used for enriching uranium.  Iran uses P-1 centrifuges, and is researching more advanced P-2 centrifuges. 

The U.N. Security Council has imposed two sets of sanctions on Iran for its refusal to stop uranium enrichment.  But world powers have agreed to put off until November efforts to seek a third set of sanctions, to see if Iran's talks with the IAEA produce results.

The United States and its allies accuse Iran of seeking to build atomic weapons under the cover of a civilian nuclear program.  Iran denies the charge.

Some information for this report was provided by AFP, AP and Reuters.