Six world powers and Iran strived at a second day of talks in Vienna yesterday to hammer out an agenda for reaching a ambitious final settlement to the decade-old standoff over Tehran’s nuc-lear programme.

The US, Russia, China, Britain, France and Germany want a long-term agreement on the permissible scope of Iran’s nuclear activities to lay to rest concerns that they could be put to developing atomic bombs.

Tehran’s priority is a complete removal of damaging economic sanctions against it.

The negotiations will probably extend over several months at least, and could help defuse many years of hostility between energy-exporting Iran and the West, ease the danger of a new war in the Middle East, transform the regional power balance and open up major business opportunities for Western firms.

“The talks are going surprisingly well. There haven’t been any real problems so far,” a senior Western diplomat said.

The opening session on Tuesday was productive and substantive, diplomats said.

“The focus was on the parameters and process of negotiations, the timetable of what is going to be a medium to long-term process,” one European diplomat said. “We don’t expect instant results.”

Iran’s Isna news agency said yesterday a draft negotiation agenda had been agreed but not yet finalised. A source among the major powers, however, said work on such a text had yet to begin.

The talks had been expected to run for at least three full days but might be adjourned today due to the escalating crisis in Ukraine, Western diplomats said.

EU foreign policy chief Catherine Ashton, who coordinates official contacts with Iran on behalf of the six, is to attend an extraordinary meeting of EU foreign ministers in Brussels on Ukraine today.

Ashton deputy Helga Schmid chaired the Vienna talks during the day with Iranian Deputy Foreign Minister Abbas Araqchi, flanked by senior diplomats from the six powers.