(Reuters) --- The parties negotiating a revival of the Iran nuclear deal agreed on Tuesday to speed up efforts to bring the United States and Iran back into compliance, diplomats said.
Iran, Britain, China, France, Germany and Russia began a third round of meetings in Vienna on Tuesday to agree steps that would be needed if the 2015 agreement, which was abandoned by former U.S. President Donald Trump in 2018, is to be revived.
The main differences are over what sanctions the United States will need to remove, what steps Iran will need to take to resume its obligations to curb its nuclear programme, and how to sequence this process to satisfy both sides.
"The discussions proved that participants are guided by the unity of purpose which is full restoration of the nuclear deal in its original form," Mikhail Ulyanov, Moscow's ambassador to the U.N. atomic watchdog, said on Twitter after senior diplomats met in the Austrian capital.
"It was decided to expedite the process."
A U.S. delegation is in a separate location in Vienna, enabling representatives of the five powers to shuttle between both sides because Iran has rejected direct talks.
Three expert working groups have been tasked with unravelling the most important issues and drafting solutions.
At the end of talks last week, the United States and its European allies said serious differences still persisted despite making some progress in their latest indirect talks.
"We hope all parties will sustain the momentum we have already reached in their efforts towards an earliest resolution of this issue before us," Wang Qun, China's envoy to the U.N. watchdog, told reporters, adding that senior diplomats would reconvene on Wednesday to take stock.
