Iran would need 2-4 months to amass bomb material: think tank

Iran would currently need at least two to four months to produce enough weapons-grade uranium for one nuclear bomb, and additional time to make the device itself, a U.S. security institute said.

Estimates of how quickly Iran could enrich its uranium to the fissile level required for bombs are closely watched as they may give an indication of how much time its foes believe they have to prevent it obtaining nuclear weapons, if and when it decided to do so, Reuters reported.

Iran says it has no such intention and that its nuclear enrichment work is purely for peaceful purposes. But its refusal to curb atomic work that can have both military and civilian purposes has drawn Western sanctions targeting its oil exports.

Although the lead times are shortening, an Iranian "nuclear breakout" to weapons capability in the next year could not escape detection by the U.N.'s International Atomic Energy Agency (IAEA) or the United States, said the report by the Institute for Science and International Security (ISIS).

Washington and its allies "maintain the ability to respond forcefully to any Iranian decision to break out", said ISIS, a Washington think-tank that tracks Iran's nuclear program.

IRAN ON THE BRINK?

Last month, Israeli Prime Minister Benjamin Netanyahu said Iran may be on the brink of having a nuclear bomb in less than a year and suggested that the Jewish state might have to make a decision on whether to use military force against its nuclear sites by spring 2013.

ISIS said Iran would need two to four months to produce the 25 kg of weapons-grade uranium needed for one nuclear weapon, but longer for the weaponisation process.