As Iran starts its uranium enrichment program at a new underground site, the nation's president set off on a tour of Latin America in a bid to rally diplomatic support.
Kayhan Daily, a leading Iranian newspaper, said on Sunday that Teheran has begun injecting uranium gas into sophisticated centrifuges at the Fordo facility near the city of Qom.
The United States and its allies accuse Iran of trying to develop bombs under cover of its nuclear program. Iran denies the allegation, saying it needs nuclear technology to generate electricity to meet its booming domestic demand.
Meanwhile, Iran is planning its next round of Persian Gulf naval drills to practice the armed forces' ability to close the Strait of Hormuz.
The elite Revolutionary Guards Corp will start naval exercises on Jan 27 in the Gulf with the aim of enhancing the country's ability to close the chokepoint into that body of water "in the shortest possible time when the situation requires it", Esmaeil Kowsari, a member of the Iranian parliament's National Security and Foreign Policy Committee, said on Saturday.
On Sunday, Iranian President Mahmoud Ahmadinejad started a four-day Latin America tour aimed at shoring up ties with his allies.
The US had declared fresh economic sanctions against Iran's central bank in an apparent bid to punish foreign companies and banks that do business with the Iranian financial institution, and the European Union is also considering measures that would forbid its member states from importing Iranian oil.
Ahmadinejad will arrive in Caracas late on Sunday, and on Tuesday he will attend the inauguration of the recently re-elected Nicaraguan President Daniel Ortega.
Stops in Cuba and Ecuador will round off the tour.
Japan has asked Saudi Arabia to provide more crude oil to compensate for any loss in shipments from Iran, the Japanese foreign ministry said after Foreign Minister Koichiro Gemba discussed the security of oil supplies and oil price stability during a visit to Riyadh.