Iran's atomic energy chief says the country has the ability to build a nuclear weapon but has no plan to, an Iranian news agency reports.

Mohammad Eslami's comments echo a similar recent statement by a senior adviser to Iran's supreme leader.

Such public claims by top officials are rare and are likely to intensify concerns over the nature of Iran's nuclear programme.

It has advanced its nuclear activities since a deal limiting them faltered.

The 2015 agreement began to unravel when the US pulled out and reinstated crippling economic sanctions.

Iran has repeatedly claimed its nuclear programme is for purely peaceful purposes but Western powers and the global nuclear watchdog say they are not convinced.

Western officials have warned time is running out to restore the deal before Iran's programme reaches such a point where it cannot be reversed.

In his remarks reported on Monday by the semi-official Fars news agency, Mr Eslami reiterated comments made by the senior adviser, Kamal Kharrazi.

"As Mr Kharrazi mentioned, Iran has the technical ability to build an atomic bomb, but such a programme is not on the agenda," Mr Eslami said.

In his own remarks made to Al Jazeera news channel on 17 July, Mr Kharrazi said: "Iran has the technical means to produce a nuclear bomb but there has been no decision by Iran to build one."

There have been growing concerns over the so-called breakout time, or the amount of time it will take Iran to amass enough highly enriched uranium for a nuclear weapon.

In June, the head of the global atomic energy agency, Rafael Grossi, said Iran could acquire such a quantity in a matter of weeks. The US put the breakout time at about a year during the period in which the nuclear deal was intact.

However Mr Grossi said possessing enough material did not mean Iran could manufacture a nuclear bomb.

In its latest report in May, the IAEA said Iran had 43.1kg (95lb) of uranium enriched to 60% purity. About 25kg of uranium enriched to 90% is needed for a nuclear weapon.

The claims from Iran that it has the technical know-how to develop a bomb come at a time when Iran and world powers are at loggerheads over reviving the 2015 deal.

Months-long on-off-talks in Vienna have stalled, and rare indirect negotiations between the US and Iran on the issue which took place in Qatar in June ended without agreement.