1137 GMT January 18, 2019
Speaking in Tehran Wednesday, as negotiators from Iran and the P5 +1 nations met in Geneva for a day of talks, mediated by the European Union, Zarif said that "good steps have been taken" and more would follow.
The negotiations were resumed more than three weeks after they last met and gave themselves another seven months to strike a deal.
Deputy Secretary General for the EU's External Action Service Helga Schmid also joined the negotiations.
"The world needs this settlement, in light of challenges facing us, like the threat of terrorism. It is in everyone's interest" Zarif said at a press conference with visiting Turkish Foreign Minister Mevlut Cavusoglu.
Meanwhile, an EU spokeswoman in the Swiss city told AFP the talks had begun, without giving further details. No announcements are expected after the discussions conclude.
The US and Iranian delegations met on Monday and Tuesday in Geneva in preparation for the multilateral talks, led by the US Acting Deputy Secretary of State Wendy Sherman and Iran's Deputy Foreign Minister Abbas Araqchi.
Earlier on Wednesday, Iranian delegation held meetings with the Russian and Chinese envoys.
Last month in the Austrian capital of Vienna, Iran and the P5+1, which comprises China, the United States, France, Russia, Britain and Germany failed to meet a November-24 deadline for a comprehensive deal.
All parties agreed to give themselves seven more months — until June 30 — to strike a deal, although they said they hoped to have the broad outlines hammered out by March.
A final agreement is aimed at ensuring Tehran's nuclear program will be peaceful, in exchange for lifting all sanctions.
Bans, Arak plant outstanding issues
A senior Russian official said illegal sanctions against Iran and the Arak heavy-water production plant are the two key outstanding issues in the nuclear negotiations.
The two issues "unfortunately, are still in the category of unresolved issues", Russian Deputy Foreign Minister Sergei Ryabkov said as he arrived in Geneva for the 11th round of Iran nuclear talks on Wednesday, Sputnik reported.
"I do not want to single out any of them with respect to other aspects not because it is hard for us to determine what is at the center and what remains on the side, but because we have been dealing with this as a package for a long time and the internal balances between the different components of the deal are very sensitive," Ryabkov stressed.
He also said that a deal between Iran and the P5+1 will help security in the region.
"Despite the attempts of some circles in the international community to question the appropriateness of this agreement…we believe that the outcome that we currently foresee for these negotiation efforts would definitely strengthen global and regional security," Ryabkov said.
The Arak reactor, which uses natural uranium to produce radio medicines, is planned to gradually replace the Tehran Research Reactor, which produces medical radioisotopes for cancer patients.
In May, Iran said the facility will remain a heavy water reactor, but will be redesigned to produce less plutonium.