Iran’s foreign minister and the European Union’s top diplomat have agreed to postpone talks on implementing a landmark nuclear agreement until after the Christmas holiday, Iran’s chief negotiator said Sunday, according to Reuters.

According to Deputy Foreign Minister Abbas Araqchi, Foreign Minister Mohammad Javad Zarif and EU foreign policy chief Catherine Ashton spoke on the phone and ” it was agreed to continue the negotiations, but with the Christmas holidays in sight it was decided to interrupt and resume (the talks) a week after the holidays.”

The Iranian nuclear negotiator said the agreement was reached during a call that lasted “45 minutes” between the two.

Araqchi said the discussions were progressing slowly because of “interpretations” of points of the agreement that Iran and world powers clinched in Geneva on November 24.

The negotiations, which are aimed at setting a framework and a timeline for the nuclear accord, stretched into a fourth day in Geneva on Sunday.

On Saturday, Araqchi said the technical talks between Iran and world powers on how to implement the deal clinched are making progress but slowly.

The negotiations resumed on Thursday in Geneva, several days after being interrupted by Iranian diplomats, who walked out over a decision by the United States to blacklist 19 more Iranian companies and individuals, which the Iranians claimed was in violation of the Geneva deal.

Zarif, meanwhile, said Sunday that little progress had been made in the talks with the P5+1 – Britain, China, France, Russia and the United States plus Germany.

“The talks on implementing the accord are not easy. They are progressing, but slowly,” he was quoted by Reuters as having told a joint news conference on Sunday with visiting Italian Foreign Minister Emma Bonino.

“I hope all sides will avoid delving into issues that could become troublesome and complicate the process,” Zarif added.

Under the deal struck on November 24, Iran agreed to roll back or freeze parts of its nuclear drive for six months in exchange for modest sanctions relief and a promise by Western powers not to impose new sanctions.

During this period, which has not yet begun, Iran and world powers will seek to hammer out a long-term comprehensive accord to allay suspicions that Tehran’s nuclear activities mask a military objective.