Iran had officially announced earlier in the day that it was resuming nuclear research after a suspension of two years.
"We call on Iran to swiftly re-establish the moratorium and to cooperate fully with the IAEA," the ministry said.
Iran informed the International Atomic Energy Agency, the UN's nuclear watchdog, last week that it would start practical work on the creation of nuclear fuel technologies, which was suspended two years ago after negotiations with the EU trio of France, Germany and Britain to consolidate the international community's faith in its nuclear program.
"The moratorium is a very important trust measure needed to solve the remaining issues relating to the Iranian nuclear program," the ministry said.
Russia is currently assisting Iran in building a nuclear reactor at Bushehr.