A prominent hardline cleric in Iran warned on Friday against the Islamic republic resuming ties with the United States, and said any attempt to do so would prove futile.

"Some people have created an underground network for establishing relations with the America," Ayatollah Ahmad Janati told crowds at Friday prayers in Tehran, in comments broadcast by state media.

"Our people are anti-American -- you should be anti-American as well. Why did you go a different way from the people?" Janati asked, addressing those alleged to be behind the move.

"As long as our people and our supreme leader do not want it, your efforts will not bear any fruit," added Janati, who heads the powerful Guardians Council electoral watchdog.

His comments sparked chants of "Death to the America!" and "Death to Israel!" from the thousands of Friday worshippers.

Supreme leader Ayatollah Ali Khamenei has the final say on all Iranian state matters including foreign policy and the nuclear issue.

Icy ties between Tehran and world powers have thawed since President Hassan Rouhani, a moderate, defeated a pool of conservatives in last June's presidential election after vowing to engage constructively with the West.

The most remarkable development to date was a 15-minute telephone conversation between Rouhani and his US counterpart Barack Obama in New York in September.

It was the first direct contact between the leaders of the two nations since diplomatic ties were severed after the US embassy hostage crisis in Tehran from 1979-1981.

But Khamenei later said he deemed part of Rouhani's New York trip as inappropriate, but without referring directly to the phone call.

The two countries' foreign ministers, Mohammad Javad Zarif and John Kerry, have also met several times, most recently at the Munich International Security Conference.

Zarif has gone so far as to tell Russian television that Washington could one day reopen its embassy in Tehran.

Iran's hardliners and many lawmakers are also critical of a landmark nuclear agreement agreed in November.

They question what Tehran stands to gain from the deal, under which it agreed to roll back parts of its controversial nuclear drive for six months in exchange for modest sanctions relief.

Western nations and the country's arch-enemy Israel have long suspected Iran of covertly seeking nuclear weapons alongside its civilian programme, an allegation denied by Tehran.

The conservative-dominated parliament has frequently summoned Zarif and other ministers for questioning on a variety of issues, including the Zarif-Kerry meetings.

Iran says expert nuclear talks to be held 'next week'
Tehran (AFP) Feb 23, 2014 - Iran and world powers will hold technical talks "next week" in Vienna ahead of a political meeting to negotiate a comprehensive nuclear deal, a top Iranian negotiator said on Sunday.

Iran and the P5+1 group of world powers agreed last week on a timetable and framework for the negotiations for an accord that would allay Western concerns about Iran's nuclear programme in return for the lifting of crippling sanctions.

"The issues on the agenda are enrichment (of uranium), the lifting of sanctions and international cooperation on peaceful nuclear energy," said Abbas Araqchi, also a deputy foreign minister.

Cited by the official IRNA news agency, Araqchi said the talks would take place on the sidelines of a meeting of the International Atomic Energy Agency's board of governors "next week".

He did not specify dates, but the board is set to meet in Vienna from March 3 to 7.

Negotiators hope to reach a final accord by July 20, when an interim agreement reached in November is due to expire.

Western nations and Israel have long suspected Iran of pursuing a nuclear weapons capability alongside its civilian programme, charges denied by Tehran.

Belgian Foreign Minister Didier Reynders, who is in Iran on an official two-day visit, expressed the hope that the talks could lead to a restoration of trust between Tehran and the West.

"I hope relationships that are based on trust will be revived with the nuclear negotiations and when a clear, final agreement is reached," he said at a news conference with his Iranian counterpart Mohammad Javad Zarif.

Under the interim deal, Iran agreed to curb parts of its nuclear programme for six months in exchange for limited sanctions relief. The agreement came into effect on January 20.

Political directors from the P5+1 group of world powers -- the United States, Britain, France, China and Russia plus Germany -- are set to resume talks with Iranian nuclear negotiators on March 17 in Vienna.

EU foreign policy chief Catherine Ashton, who is coordinating P5+1 negotiators in the talks, will visit Tehran on March 9 and 10, according to Iranian media reports.

Confirming the reports, Araqchi said Ashton would be on an official mission representing the European Union.

"Mrs Ashton will travel to Iran as the high representative for the European Union and not as the coordinator for the P5+1," he said.

"But naturally, the nuclear issue will be on the agenda," Araqchi added.