Iran froze all United Nations nuclear inspections for six weeks on Friday, throwing into doubt the delivery date of a report on the country's nuclear program.

Inspectors with the International Atomic Energy Agency (IAEA) are to deliver a report by June on whether Iran's nuclear program is being developed to create atomic energy or weapons.

Pirooz Hosseini, Iran's representative to the IAEA, said the inspections were postponed because of next week's Iranian New Year celebrations.

UN inspectors were due to return to Iran next week to resume inspections. A spokesperson for IAEA declined to comment on the freeze.

Last month, an IAEA report said Iran is hiding evidence of nuclear experiments, saying inspectors had discovered traces of an element used in nuclear weapons.