Russia's Deputy Foreign Minister Sergei Ryabkov has said Iran and world powers are close to a nuclear agreement.
TASS news agency quoted Ryabkov as saying in Vienna on July 2, "All parties are of the opinion that this matter will be resolved in the coming days."
Russia's top negotiator also said that the visit to Tehran by the director-general of the International Atomic Energy Agency (IAEA), Yukiya Amano, helped to bring "greater clarity" to the negotiations.
Negotiators from Iran, Britain, China, France, Germany, Russia, and the United State are working to strike a deal under which Tehran would curb its nuclear program in exchange for sanctions relief.
The parties have given themselves until July 7 to reach agreement.
The six powers want limits on Iran's nuclear programs that could have a military use. Tehran denies it is pursuing atomic weapons.
Earlier on July 2, France's foreign minister told reporters in Vienna that he would return to the Austrian capital on the evening of July 7 in the hope that sufficient progress has been made to reach a final nuclear deal.
"Things have advanced, but we have not yet reached the end," Laurent Fabius said before leaving for Paris. "I hope that at that stage we will be in a situation to move, perhaps, and I hope so, to find a definitive solution that will enable a robust agreement."
Meanwhile, Chinese Foreign Minister Wang Yi has said there is a "high possibility" that Iran and major powers will agree to a comprehensive nuclear accord in the coming days.
Wang was speaking to reporters on July 2 on arrival in Vienna.
Wang said all sides need to make "positive efforts," adding that there are still “some important and sensitive issues which no one can shy away from."