High level officials from the United States, Britain, China, France, Germany and Russia met with Iran's deputy foreign minister Abbas Araghchi for a day of talks as part of "ongoing diplomatic efforts to find a comprehensive solution to the Iranian nuclear issue," the European Union yesterday said in a message sent to journalists.
"They had serious and useful meetings chaired by EU political director Helga Schmid and decided to meet again in early February," the message said.
Following an interim accord agreed in Geneva in November 2013, two deadlines for a final deal have been missed, and now a third one is looming on July 1.
Araghchi had met with senior US officials for three days prior to yesterday's meeting and also met with Russian officials in preparation for the thorny talks.
"We remain hopeful, and I think that if the other side has the necessary good will and determination it will be possible to reach a deal," he told the Fars news agency Saturday.
Iranian Foreign Minister Mohammad Javad Zarif meanwhile warned Saturday that progress towards a deal would only be reached if the so-called P5+1 global powers "stop with the pressure" on Iran.
Among issues complicating negotiations are hardliners in Washington and Tehran who appear willing to torpedo the efforts.
The new Republican-controlled US Congress is considering a fresh sanctions bill, despite strong opposition from President Barack Obama, who has threatened to veto any such legislation that lands on his desk.
Yesterday, supporters of Iran sanctions in the Senate unveiled a toned-down bill aimed at gaining enough votes to override a presidential veto.
If a sanctions bill does go through, some Iranian lawmakers hinted that they could push to resume unlimited uranium enrichment.