European Union foreign ministers say a "swift implementation of voluntary measures by all sides" is key in nuclear talks between Iran and six world powers.
The ministers, meeting in Brussels, said in a statement on December 16 that Iran has to implement "its commitments in good faith."
The statement said the European Union remains committed to the suspension of EU sanctions immediately after the UN nuclear agency verifies the implementation of the nuclear-related measures by Tehran.
Earlier, EU foreign policy chief Catherine Ashton reiterated optimism that the nuclear talks would be resumed soon.
She said most of the details for resuming negotiations had been "sorted out."
The talks were halted last week for "consultations" after Washington added more names to a blacklist aimed at preventing Iran from obtaining the means to construct nuclear weapons.