The United States has accused Iran of repeated violations of its UN nuclear safeguards agreement and demanded Tehran unconditionally accept tighter UN inspections of its atomic facilities.

The US ambassador to the United Nations in Vienna, Kenneth Brill, questioned why, if Iran's intentions are peaceful, did the country engage in a long-term pattern evasions regarding a number of its nuclear activities.

Mr Brill was speaking at a debate on a report by the International Atomic Energy Agency on 12 years of failures by Iran to comply with its nuclear safeguards agreement.