Iran warned Tuesday that any attack on its nuclear power plant would be an "international crime."
The head of Iran's nuclear agency, Ali Akbar Salehi, issued the warning in an interview with Iranian media as the country prepares to start up a Russian-fueled reactor for the first time.
Iran is planning to launch the Bushehr power plant on August 21, using fuel delivered by Russia. The plant would begin generating electricity days after that.
Iran says observers from the United Nations International Atomic Energy Agency will supervise the process.
Iran is under four sets of U.N. sanctions for its nuclear program, which the United States and other countries say is aimed at creating a weapon. Tehran says its nuclear program is for peaceful purposes.
The sanctions are in reaction to Iran's refusal to stop enriching uranium - a process that eventually can create the material for a nuclear bomb. Iran says it is only trying to process fuel to power civilian reactors.
On Monday, White House spokesman Robert Gibbs said the nuclear fuel arrangement with Russia shows there is no need for Iran to enrich its own uranium.
Meantime, the former U.S. representative to the United Nations, John Bolton, told Fox News that Israel has until August 21 to attack the Bushehr facility. He said after that point there is too high a risk of spreading radiation. Bolton added that he does not think it is very likely Israel will actually launch an attack in the next week.
Israel is one of the harshest critics of Iran's nuclear program, and fears Iranian possession of an atomic weapon could lead to the destruction of the Jewish state.
Some information for this report was provided by AFP.