Iran and six world powers on Thursday were approaching the final stretch in marathon talks aimed at restricting the country's nuclear programs in exchange for sanctions relief.
The sides are aiming to have a deal by June 30. But with less than four weeks to go, some negotiators have said the talks might go beyond that date.
Any deal would cap nearly a decade of international efforts to restrict Iranian nuclear programs that could be turned toward making weapons. Tehran denies any interest in atomic arms, but wants an end to international sanctions.
Russian Foreign Minister Sergey Lavrov, who met Iranian Foreign Minister Mohamad Javad Zarif on Thursday, said in comments carried by Russian news agencies that Russia is working hard to contribute to the long-anticipated deal and called on others to help bring forward the resolution by the agreed date.
"The talks have entered the final stage and we are convinced that the parties ought to reach agreement on all technical issues in order to comply with the already agreed political framework,'' he said, quoted by Tass.
The talks in Vienna on Thursday involve senior officials from Iran, the United States, Russia, China, Britain, France and Germany and follow a day of experts' meetings.