Tehran, Apr 15 (IANS): Iran has no problem negotiating the return to the 2015 nuclear agreement, but will do so "according to its own logic", President Hassan Rouhani said during a cabinet meeting.

"We are not in a hurry for negotiations to be held today or tomorrow, and that depends on the other part. We are ready and our position is clear," Xinhua news agency quoted Rouhani as saying on Wednesday while referring to the nuclear talks in Vienna.

The US, he said, must implement the very same conditions that were agreed in July 2015, and as soon as Iran verifies those conditions have been met, it will "immediately fulfil all (its) obligations".

The Iranian government, Rouhani added, has already made plans for the verification procedures, so verifying the compliance will not take long.

Commenting on the upgrade of Iran's uranium enrichment at the nuclear plant in Natanz, Rouhani described the move as the "first response" to the "mischiefs" of Tehran's enemies, after an explosion was reported in the facilities on Sunday.

Analysts said the incident at the enrichment plant has complicated efforts to rescue the 2015 deal, officially known as the Joint Comprehensive Plan of Action (JCPOA), with lifting sanctions on Iran and nuclear implementation measures on the top of the agenda.

On Tuesday, Iranian chief nuclear negotiator Abbas Araqchi said the country has notified the International Atomic Energy Agency (IAEA) that Iran plans to start uranium enrichment at 60 per cent purity and add 1,000 advanced centrifuges to its enrichment devices in Natanz.

The explosion was "apparently" the work of Israel, the President said at the cabinet meeting.

He described the incident in Natanz an act of "nuclear terrorism" aimed at disrupting Iran's "peaceful legal technology under IAEA oversight", but Iran will continue to work "legally" within that framework.

In any case, Rouhani said, the IAEA will continue to monitor Iran's enrichment activity whatever the degree of purity is.

Under the JCPOA, Iran is allowed to enrich uranium only up to a 3.67 per cent of purity and its stockpile should not be more than 300 kg.

However, Iran has been scaling down its compliance to its JCPOA obligations since the US withdrew from the deal in May 2018 and re-imposed sanctions on the country.

On January 4, Iran started to produce uranium enrichment of 20 per cent purity.