Iran's new atomic energy chief Mohamed Eslami on Monday called on the United States to "rectify their wrong policies" and lift sanctions, at the opening of the UN nuclear watchdog's annual conference.

Eslami set the tone of Iran's new ultraconservative president Ebrahim Raisi in his first remarks to the 173-member International Atomic Energy Agency (IAEA) conference.

Negotiations that began earlier this year to revive a 2015 landmark agreement that offered Iran sanctions relief in exchange for curbs on its nuclear programme have not resumed since Raisi took power last month. 

Raisi's government wanted "results-oriented negotiations with the goal of lifting the unjust pressure and sanctions imposed on (the) Iranian nation," said Eslami, the Iranian Atomic Energy Organization (AEOI) chief.

"Now it is time for the US to rectify their wrong policies and initially remove all sanctions in a practical, effective and verifiable manner," he said, insisting that the Islamic republic's nuclear programme was peaceful.

Iran has stepped up its nuclear activities since 2019, a year after then US president Donald Trump left the 2015 agreement and reimposed sanctions.

Earlier this year, talks with the remaining parties to the deal -- Britain, France, Germany, China and Russia -- began in Vienna with indirect US participation.

The negotiations aim to bring Washington back to the agreement and lift sanctions, while Iran again cuts back its nuclear programme.