Iran’s nuclear weapons drive must be stopped before it has amassed enough 20%-enriched uranium for a single bomb, Prime Minister Benjamin Netanyahu indicated on Friday.

On Thursday, in a speech to the United Nations illustrated with a cartoon bomb, Netanyahu called for a red line to be set for Iran’s uranium enrichment process. Pressed specifically in an interview on Israel’s Channel 2, as to whether this meant an attack would have to come before Iran had enriched 240 kg (529 lb) of uranium to 20% purity — enough for one bomb — Netanyahu did not contest the figures.

Prime Minister Benjamin Netanyahu sets out his 'red line' for Iran on a cartoon bomb drawing during a September 27 speech to the General Assembly (photo credit: Avi Ohayun, GPO)

Prime Minister Benjamin Netanyahu sets out his ‘red line’ for Iran on a cartoon bomb drawing during a September 27 speech to the General Assembly (photo credit: Avi Ohayun, GPO)

He also said he did not discount the possibility of an Israeli or American attack on Iran’s nuclear facilities before Spring 2013, “if [Tehran] continues at the current rate” of enrichment.

“Let’s see if they continue,” Netanyahu said, and reiterated that setting a red line “could prevent the need for a military operation.” He stressed that Israel, while it is closely coordinating with the US, reserves all its “rights and freedoms to act as we see fit.”

According to an IAEA report published on August 30, Iran has enriched 189 kg of uranium hexafluoride gas to 20% purity, up 43.8 kg since May’s 145 kg estimate. Channel 2 placed its current stock at 150-170 kg.

Netanyahu spoke at length on Friday with US President Barack Obama, and the prime minister remarked in the TV interview that “Israel and the United States can arrive at a far more unified understanding than what was apparent to pundits as of late.”

The White House said that the two heads of state “discussed a range of security issues, and the President reaffirmed his and our country’s unshakable commitment to Israel’s security. The two leaders underscored that they are in full agreement on the shared goal of preventing Iran from obtaining a nuclear weapon.”

Israeli sources said the conversation was good and not confrontational. Obama, in a phone call earlier this month, reportedly rebuffed a direct request from Netanyahu to set out red lines for Iran. He also did not meet with Netanyahu on the prime minister’s current brief trip, with the White House claiming at one point that no meeting had been requested and then citing scheduling difficulties.

Netanyahu also spoke Friday with Republican presidential candidate Mitt Romney.