Tehran says "positive steps" have been made at its just-concluded nuclear talks with world powers here and some of the proposals presented by its counterparts are "more realistic."

"Some of the points raised in their response were more realistic compared to what they said in the past," said Saeed Jalili, Iran's chief nuclear negotiator to the Iran-P5+1 talks.

The six world powers that constitute P5+1, the United States, Britain, France, Russia and China -- plus Germany, offered to ease some sanctions on Iran in exchange for concessions on its disputed nuclear program.

"They tried to bring proximity in some points between the viewpoints of Iran and their own, which we believe is a positive step, despite the fact that we have a long way to reach the optimum point," Jalili said.

He reiterated that, as a member of the nuclear Non-Proliferation Treaty (NPT), Iran had the right to enrich uranium based on its need, which was only for peaceful use.

The two sides agreed to hold another Iran-P5+1 meeting here this April after their nuclear experts meet in Istanbul in March.