The top foreign adviser to Iran's supreme leader has called for new direct talks with the United States to ease crippling sanctions imposed on Tehran, amid the multilateral negotiations over Iran's nuclear programme.

Ali Akbar Velayati said on Friday that Tehran should talk separately with each of the so-called 5+1 powers, which include the US. 

"We aren't on the right path if we don't have one-on-one talks with the six countries," Velayati said, according to the semi-official Mehr news agency.

The remarks signalled a high-level endorsement of the policies of Iran's President Hassan Rouhani, whom hard-liners have criticised over last month's nuclear deal and other contacts with the US.

The 5+1 grouping of the US, Russia, France, Britain, China and Germany has still to work out a permanent accord with Iran to set a framework and a timeline for the November 24 deal.

Technical talks 

Meanwhile, Abbas Arachi, Iran's senior negotiator, said on Friday that experts from Iran and the world powers would hold a new round of talks on Monday.

"The technical discussions between Iran and the 5+1 group will resume Monday in Geneva... to define modalities for implementing the agreement," Arachi said.

A spokeswoman for EU foreign policy chief Catherine Ashton also confirmed the December 30 meeting.

Under the Geneva accord, Iran agreed to roll back or freeze parts of its nuclear drive for six months in exchange for modest sanctions relief and a promise by Western powers not to impose new sanctions.

Western powers suspect Iran's nuclear activities mask military objectives, despite Tehran's repeated insistence that they are entirely peaceful.

Source: Agencies