Iran is insisting it will resume uranium conversion this week, after rejecting European incentives to end its nuclear fuel work.
Speaking Sunday in Tehran, a Foreign Ministry spokesman said work at Iran's Isfahan nuclear plant will begin once the International Atomic Energy Agency installs surveillance cameras. The IAEA says inspection equipment will be in place by mid-week.
British, French and German negotiators have called an emergency meeting of the IAEA on Tuesday to issue Tehran a final warning against restarting the fuel program.
Western governments suspect Iran's nuclear activities are aimed at developing atomic weaponry. Tehran insists its nuclear intentions are peaceful.
If the stand-off continues, the Europeans say they will ask the U.N. Security Council to consider imposing economic sanctions to force Tehran to end its fuel work.
Some information for this report provided by AFP and Reuters.