He added that he thought such an attack is unlikely and that the Russian-built facility represents a major step forward for Iran's nuclear weapons aspirations.

Bolton told the Fox Business Network on Monday that if Israel wants to prevent Iran from acquiring a working nuclear plant, a military strike must be launched against the Bushehr nuclear power facility within the next week.

Sergei Novikov, spokesman for Russia’s state nuclear corporation, Rosatom, said last week that the Bushehr plant would be loaded with nuclear fuel on Aug. 21.

Bolton warned that after that date it will be too late for Israel to launch a military strike against the facility because any attack would spread radiation and affect Iranian civilians.

In the interview, Bolton also said that the completion of the reactor was a "significant victory for Iran."

"They will be beginning the process of bringing online a 1000 megawatt reactor. When it becomes fully operational the spent fuel coming out of the reactor will be plutonium which could be reprocessed chemically and used for nuclear weapons," Bolton said.

He added that Iran was "on the verge of achieving something that Saddam Hussein was not able to achieve, Bashar Al-Assad in Syria was not able to achieve and that's getting a second route to nuclear weapons."

"Once the fuel rods are inserted into the reactor any attack on the reactor would almost certainly release radiation into the atmosphere, given where Bushehr is located right on the Arabian Gulf possibly into the water as well," Bolton said.

"So if Israel is going to do anything against Bushehr it has to move in the next eight days."

The controversial former envoy to the United Nations criticized Russia's role in the development of the plant, saying: "The Russians are, as they often do, playing both sides against the middle."

Iran warned Tuesday that an attack on the plant would amount to an "international crime." "Attacking an international plant is an international crime as the consequences will not be limited to the hosting country but will have a global aftermath," Iran's nuclear chief Ali Akbar Salehi told the state IRNA news agency.

Iran's Foreign Ministry spokesman dismissed a possible Israeli attack on the Bushehr plant. "These threats have become repetitive and lost their meaning," Ramin Mehmanparast told reporters.

— With input from agencies