Iran on Sunday agreed to seven more "practical steps" with the UN nuclear watchdog in talks seeking further safeguards to enhance transparency on Tehran's nuclear drive, a top official said.

The deals need to be implemented by May 15, Iran's envoy to the International Atomic Energy Agency (IAEA) Reza Najafi said.

Najafi said "constructive technical meetings" had assessed "the progress in implementation of practical steps" that was required of Iran under a framework deal agreed on November 11, 2013.

The deal required Tehran to take six practical steps that included visits to the unfinished site of a so-called heavy water research reactor in Arak and a uranium mine in the south.

Also required from Iran was information on future research reactors, identifying sites of new nuclear power plants, and clarification on Iranian statements regarding additional enrichment facilities and laser enrichment technology.

"None of the nuclear sites will be shut down or dismantled," said Asghar Zare'an, deputy chief of Atomic Energy Organization of Iran for Protection and Security.

The IAEA is also seeking access to the Parchin military facility where it suspects Tehran may have experimented with research related to atomic weapons development.

But Iran's Atomic Energy Organization spokesperson Behrouz Kamalvand said that visiting the Parchin military site is not included in the Sunday agreement.

The IAEA talks are running in parallel with efforts by the so-called P5+1 group seeking a comprehensive accord with Iran that would resolve the decade-long impasse over its nuclear work.

Separately, Iranian Admiral Afshin Rezayee Haddad said Saturday that a number of warships had been ordered to approach US maritime borders as a response to the stationing of US vessels in the Gulf, the Fars news agency reported.

The Fars report, which carried no details of the vessels, could not be confirmed independently.

A US defense official, speaking on condition of anonymity, cast doubt on any claims that the Iranian ships were approaching US maritime borders. But the official added that "ships are free to operate in international waters."

Agencies