Iran has taken "initial steps" to design its first nuclear-powered submarine, a deputy navy commander claimed in an interview with the Fars news agency published on Tuesday.

"Initial steps to design and build nuclear submarine propulsion systems have begun," Admiral Abbas Zamini, the technical deputy navy chief, told the agency.

"All countries have the right to use peaceful nuclear technology, including for the propulsion system of its vessels," he said.

Iran's navy "needs the (nuclear-powered) propulsion system to succeed in realising very long-distance operations."

He did not provide further details.

Iran regularly boasts about advances in military and scientific fields, but in most cases fails to provide proof they were ever carried out. Western military experts regularly cast doubt on its claims.

Just a handful of nations -- the United States, Russia, France, Britain and China -- have the technology to make their own nuclear-powered submarines. India has a model under development.

The navy official's announcement comes as the P5+1 group of world powers are preparing for a new round of crunch talks with Iran in Moscow on June 18 and 19 over Tehran's disputed nuclear activities.

Iran is pushing forward with an ambitious nuclear programme despite UN Security Council resolutions demanding a halt to uranium enrichment.

The nuclear programme is at the heart of a decade-long standoff between a defiant Tehran and Western powers that fear the Islamic regime is covertly conducting research for atomic weapons capability.