Tehran and Moscow inaugurated on Sunday a new phase of construction for a second reactor at Iran's sole nuclear power plant in Bushehr.
Ali Akbar Salehi, head of the Atomic Energy Organization of Iran (AEOI), and deputy chief of Russia's nuclear agency Rosatom, Alexander Lokshin, launched the new stage at a ceremony where concrete was poured for the reactor base.
The reactor is one of two officially under construction since 2017 at the Bushehr site that is around 750 kilometers south of Tehran, Agence France Presse reported.
The landmark 2015 nuclear deal Iran signed with six major powers, including Russia, placed restrictions on the sort of nuclear reactor Tehran could develop and its production of nuclear fuel but it did not require Iran to halt its use of nuclear energy for power generation.
"In a long term vision until 2027-2028, when these projects are finished, we will have 3,000 megawatts of nuclear plant-generated electricity," Salehi said at the ceremony.
Iran has been seeking to reduce its reliance on oil and gas through the development of nuclear power facilities.
Russia built the existing 1,000 megawatt reactor at Bushehr that came online in September 2011 and is expected to undertake construction of a a third in future, according to the AEOI.
As part of the 2015 agreement, Moscow provides Tehran with the fuel it needs for its electricity-generating nuclear reactors.
Intended to guarantee that Iran's long-controversial nuclear program would never be used for military purposes, the survival of the deal has been under threat since the United States unilaterally withdrew from the agreement in May 2018, reimposing biting sanctions.
In response to the sanctions, which deprive Iran of anticipated benefits from the deal, Tehran began walking back on its commitments from May this year.
Also Sunday, Iran's Foreign Ministry rejected as a "trap" reports that the International Atomic Energy Agency, the UN's nuclear watchdog, found traces of uranium at an Iranian site that Israel called a "secret atomic warehouse".
Two months after Reuters first reported that samples taken at the site had shown traces of uranium, the IAEA on Wednesday told member states at a closed-door briefing that it had found uranium traces at a site in Iran it did not name, but diplomats at the meeting said it was clearly the same place.
"The Zionist regime and Israel are attempting to re-open … this file," Iranian Foreign Ministry spokesman Abbas Mousavi said in remarks carried on state television.
"We have announced that this is a trap," Mousavi said. "Hopefully the IAEA will maintain its vigilance."
The IAEA confirmed to member states that the traces from samples taken in February were of uranium that was processed but not enriched, and that the explanations provided by Iran so far did not hold water, diplomats said.
In 2018, Israeli Prime Minister Benjamin Netanyahu, who vehemently opposed the nuclear deal, called on the IAEA to visit the site immediately, saying it had housed 15 kg of unspecified radioactive material that had since been removed.