President Rouhani dismissed the US and the three major European countries' concerns after Iran's announcement of starting uranium enrichment to 60% level as "wrong".

He blamed the other parties to the nuclear deal for Iran's latest move, and stressed that as soon as the other parties abide by their undertakings under the deal, Iran will reverse course and will stop both 20% and 60% enrichment.

Rouhani also underscored that the US and Europeans are not in a position to accuse Iran of seeking nuclear weapons. 

"We could have done 60% (enrichment) before. Today we can do 90% enrichment if we want to, but we are not seeking a nuclear bomb," he added.

Stressing that Iran is only pursuing peaceful nuclear activities, Rouhani underlined, "It is you who have been seeking nuclear bombs for years, stockpiling them, and building new bombs every year."

"Whenever you return to the JCPOA undertakings, we will return to ours immediately and our enrichment will not be above 3.67% as allowed by the JCPOA," he said.

His comments came days after an incident was reported at a part of the power network of the Natanz nuclear facility on Sunday morning.

The incident at the power distribution network of Shahid Ahmadi Roshan facility in Natanz has been blamed on Israel. While Tel Aviv officials have made implicit confession of the terrorist attack, the Israeli state and private media have acknowledged Mossad's leading role in the attack.

Iranian officials have vowed retaliation against perpetrators, specially Israel.

Iran’s Permanent Representative to Vienna-based International Organizations Kazzem Qaribabadi slammed Israel as the main culprit behind the recent incident in Natanz nuclear facility, adding that the act of sabotage will not stop enrichment activities in the complex.

“The full responsibility for this act of sabotage lies with the Zionist regime of Israel and its supporters,” Qaribabadi, who is also Iran’s envoy to the International Atomic Energy Agency (IAEA), said in a televised interview, adding the damaged IR-1 centrifuges would be replaced in no time with others capable of 50 percent more enrichment capacity.

He stressed that the latest generation of homegrown centrifuges would also be set up in the nuclear facility in the near future.

In a first move to show Iran's hardening stance in reaction to the Sunday terrorist attack on Natanz nuclear facility, the country declared on Tuesday that the Atomic Energy Organization of Iran (AEOI) will initiate preparatory steps to start enriching uranium to the 60% purity level.

"Upon an order by the President, the AEOI has been required to launch 60-percent uranium enrichment line under Article 1 of the Parliament Law on 'Strategic Action to Remove Sanctions' and protect the Iranian nation's interests," AEOI Spokesman Behrouz Kamalvandi told FNA on Tuesday night.

He further added that the International Atomic Energy Agency has been informed of Iran's plan, and pointed out that the 60-percent enriched uranium is used in the production of Molybdenum to be used for the production of different types of radiomedicine, with applications in the treatment of patients including those with cardiac problems.

The spokesman further explained about the preparatory steps to be taken tonight, and said executive plans will go under development to replace the damaged IR1 centrifuges with new machines with a 50-percent higher capacity due to their quality improvements.

Meantime, Iranian Deputy Foreign Minister Seyed Abbas Araqchi who leads the country's negotiating team in talks with the G4+1 (Russia, China, UK and France plus Germany) in Vienna confirmed the launch of 60-percent enrichment on Tuesday.

"Iran has informed the IAEA director general in a letter today that it plans to start 60-percent enrichment," said Araqchi, who is now in Vienna for a second round of talks with members of the Joint Commission of the Joint Comprehensive Plan of Action (JCPOA) on the removal of the US sanctions as a first step to revive the nuclear deal.