Six world powers met with negotiators from Iran in Kazakhstan on Tuesday to discuss Iran's highly contested nuclear program.
Western negotiators proposed small concessions in exchange for an easing up of sanctions against Tehran, yet no details of the proposal have been divulged.
"The Iranians went away to consider our proposal during the course of the afternoon and the evening," said Michael Mann, spokesman for EU foreign policy chief Catherine Ashton, who is leading the negotiations. "There was a useful discussion on that proposal."
He said Iran is "in breach of their international obligations, therefore the onus is on them to begin the process of building confidence."