Iran says it is planning to begin building two new uranium enrichment facilities.
Iranian state media quote the head of Iran's nuclear program, Ali Akbar Salehi, saying Monday that construction should start in the next Iranian year, which begins in March.
Iran announced plans in November to build 10 new enrichment plants in addition to its existing facility in Natanz, as the country continues to defy international calls to halt enrichment.
Israeli Prime Minister Benjamin Netanyahu reiterated his calls for an immediate embargo on Iran's energy sector Monday, regardless of whether the U.N. Security Council can agree on the move.
Mr. Netanyahu said he is not sure if energy sanctions will curb Iran's behavior, but he said members of the international community should at least try the harsh sanctions because "nothing else will be effective."
Last week in Moscow, Mr. Netanyahu asked Russian President Dmitry Medvedev to back "sanctions with teeth" that will punish Iran's energy sector for Tehran's controversial nuclear program.
The United States and other world powers fear Iran's increased enrichment work could be aimed at creating a nuclear weapon. Tehran insists its nuclear program is for peaceful purposes only.
Washington has been leading efforts to impose a fourth round of U.N. sanctions against Iran for its nuclear activities.
On Sunday, U.S. General David Petraeus said the United States will increase pressure on Iran, saying it has given Tehran every opportunity to resolve the dispute through diplomacy.
General Petraeus is head of the U.S. Central Command, which overseas American forces in Iraq and Afghanistan.
Speaking on U.S. television he said the United States is on a "pressure track" to persuade Iran to slow its nuclear program.
Some information for this report provided by AFP, AP and Reuters.