Iran and six world powers have agreed on an agenda for negotiations over Tehran's disputed nuclear program and will meet again in March in Vienna, a senior Iranian official was quoted as saying.

Negotiators from Iran and the powers - the United States, France, Germany, Britain, China and Russia - have been meeting since Tuesday, Feb 18, in the Austrian capital to hammer out an agenda for reaching an ambitious final settlement to the decade-old standoff over Tehran's atomic activities.

According to a Reuters report, Iranian Deputy Foreign Minister Abbas Araqchi told the official IRNA news agency: "The involved parties have agreed on an agenda and a framework and the next round of talks will be in the second half of March in Vienna."

A senior U.S. state department official earlier said about the second day of talks on Wednesday: "Today's discussions, which covered both process and substance, were constructive and useful."

The meeting was due to resume on Thursday morning, expected to be followed by a news conference.

The six powers 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 at least over several months 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.