Britain published a review of foreign and defence policy on Tuesday that unveiled plans to bolster its arsenal from 180 warheads to 260 by the end of the decade, reversing a previous commitment to reduce its stockpile.

The announcement came after Britain had repeatedly criticised Iran for resuming parts of its civil nuclear programme which it had given up under a 2015 deal abandoned by former US president Donald Trump but now broadly supported by his successor Joe Biden.

"In utter hypocrisy, (British Prime Minister) @BorisJohnson is 'concerned about Iran developing a viable nuclear weapon'," Iran's Foreign Minister Mohammad Javad Zarif complained in a tweet.

"On the very same day he announces his country will increase its stockpile of nukes.

"Unlike the UK and allies, Iran believes nukes and all WMDs (weapons of mass destruction) are barbaric & must be eradicated."

Under the terms of the nuclear Non-Proliferation Treaty, which went into effect in 1970, Britain is one of a handful of recognised nuclear powers.

Fellow signatory Iran has no such recognition and committed itself never to acquire or manufacture a nuclear weapon.

Iran has consistently denied any such ambition although its arch foe Israel, which is widely suspected of maintaining its own undeclared nuclear arsenal, has repeatedly accused it of covertly seeking the bomb.

The 2015 nuclear deal with Iran, which Britain and other European governments are seeking to revive, was an attempt to assuage such concerns.

Britain's announcement also drew criticism from Russia, which was identified in the review as the "most acute direct threat to the UK".

"We are very sorry that the UK has chosen this path of increasing nuclear warheads. This decision harms international stability and strategic security," Kremlin spokesman Dmitry Peskov told reporters.

"The presence of nuclear warheads is what threatens peace throughout the world."