"This morning Iran passed the 4.5 percent level in uranium enrichment," Kamalvandi said according to the semi-official ISNA News Agency.

"This level of purity completely satisfies the power plant fuel requirements of the country," he added in a hint that the Islamic republic might stick to this level of enrichment for the time being.

Iran announced on Sunday it would no longer adhere to the enrichment cap in what it billed as its second step to decrease commitments to the deal in a bid to press other parties into keeping their side of the bargain.

US President Donald Trump withdrew from the deal between Iran and six world powers in May 2018 and has since reimposed sanctions on many sectors including the crucial oil and financial industries.

Iran demanded the other parties -- France, Germany, Britain, China and Russia -- take steps to guarantee the economic benefits Iran was promised for the drastic limitations imposed on its nuclear programme.

However after one year of what it called "strategic patience", Tehran has grown increasingly frustrated about a perceived lack of action by the European side to help it economically in the face of crippling US sanctions.