By Frances Harrison
BBC News, Tehran
Iran has threatened to resume the enrichment of uranium.
Iran faces the threat of sanctions if it does not halt its nuclear plans
Iran wants a resolution passed by the International Atomic Energy Agency, paving the way for referral to the UN Security Council, to be amended.
Foreign ministry spokesman Hamid Reza Asefi did not give any time frame for Iran to start enrichment.
Iran has already warned that if the IAEA insists on implementing its latest resolution, then its spot inspections of Iranian nuclear sites will end.
Now Mr Asefi says Iran will also start up its enrichment programme if the IAEA resolution is not amended - something bound to alarm the international community.
The IAEA resolution has given Iran one last chance to build confidence by stopping all its nuclear activities and allowing even more access to UN inspectors.
NUCLEAR FUEL CYCLE
Mined uranium ore is purified and reconstituted into solid form known as yellowcake
Yellowcake is converted into a gas by heating it to about 64C (147F)
Gas is fed through centrifuges, where its isotopes separate and process is repeated until uranium is enriched
Low-level enriched uranium is used for nuclear fuel
Highly enriched uranium can be used in nuclear weapons
Iran is now threatening to do the exact opposite of what it has been asked.
And there was also a warning for countries that did not vote in favour of Iran at the recent IAEA board meeting.
The Foreign Ministry spokesman said Iran would reconsider economic ties with some of these countries, depending on the state of relations.
Tehran has expressed particular surprise at India's decision to vote against Iran when the two countries are working on a major gas deal.