Updated at 4:02 p.m. ET
(CBS/AP) UNITED NATIONS - Israeli Prime Minister Benjamin Netanyahu warned Thursday that Iran will have enough enriched uranium to make a nuclear bomb by next summer and urged the world to draw a clear "red line" to stop it in its tracks.
Saying it was getting "late, very late" to stop Iran, Netanyahu flashed a diagram showing the progress Iran has made toward creating a bomb.
"At this late hour, there is only one way to peacefully prevent Iran from getting atomic bombs, and that is by placing a clear red line on Iran's nuclear weapons program," Netanyahu said.
He said Iran had already completed the first stage of uranium enrichment, and then he drew his own red line on the diagram to highlight the point of no return the completion of the second stage and 90 percent enrichment.
"Iran is 70 percent of the way there and ... well into the second stage. By next summer, at current enrichment rates, they will have finished the medium enrichment and move on to the final stage," Netanyahu said. "From there it is only a few more weeks before they have enriched enough for a bomb."
Netanyahu has repeatedly argued that time is running out to stop the Islamic Republic from becoming a nuclear power and the threat of force must be seriously considered.
"I believe that faced with a clear red line, Iran will back down and it will give more time for sanctions and diplomacy," the Israeli prime minister said. "Red lines don't lead to war, red lines prevent war ... nothing could imperil the world more than a nuclear-armed Iran."
Netanyahu's speech marks perhaps his final plea before Israel takes matters into its own hands. Israeli leaders have issued a series of warnings in recent weeks suggesting that if Iran's uranium enrichment program continues it may soon stage a unilateral military strike, flouting even American wishes.
The Obama administration has urgently sought to hold off Israeli military action, which would likely result in the U.S. being pulled into a conflict and cause region-wide mayhem on the eve of American elections.
Israel considers a nuclear-armed Iran to be an existential threat, citing Iranian denials of the Holocaust, its calls for Israel's destruction, its development of missiles capable of striking the Jewish state and its support for hostile Arab militant groups.
"Given this record of Iranian aggression without nuclear weapons, just imagine Iranian aggression with nuclear weapons," Netanyahu said.
Iran insists its nuclear program is for peaceful purposes but Israel, the U.S. and other Western allies reject the claim. Four rounds of U.N. sanctions have already been placed on Iran.
A U.N. report last month only reinforced Israeli fears, finding that Iran has moved more of its uranium enrichment activities into fortified bunkers deep underground where there are impervious to air attack. Enrichment is a key activity in building a bomb, though it has other uses as well, such as producing medical isotopes.
While Israel is convinced that Iran is pursuing a nuclear weapon, American officials believe Iran has not yet made a final decision to take the plunge, even as it develops much of the infrastructure needed to do so.
President Obama has repeatedly said he will not allow Iran to gain nuclear weapons and has said the U.S. would be prepared to use force as a last resort. But in an interview Sunday with CBS' "60 Minutes" he also vowed to "block out any noise that's out there" on the issue, in an apparent swipe at Netanyahu.
(Below, watch Part 1 of Mr. Obama's interview with Steve Kroft)
Netanyahu claims international diplomatic efforts and economic sanctions have failed, but a new report from the Israeli Foreign Ministry, leaked Thursday, concludes that sanctions are hitting Iran hard. According to the report, details of which appeared in the Haaretz newspaper, Iran's oil exports declined by over 50 percent in the past year and sanctions on Iran's central bank have made it difficult for the regime to access its foreign currency.
An Israeli official confirmed the new report but refused to elaborate on it. The official spoke on condition of anonymity because he was not authorized to discuss internal government documents.
A few hours before Netanyahu flew to the U.S., Iranian leader Mahmoud Ahmadinejad, known for past fiery denunciations of the United States and Israel, spoke at length about his vision for a "new world order" during his speech at the U.N. His speech on Wednesday happened to fall on Yom Kippur, the most sacred day on the Jewish calendar, devoted to fasting, prayer and introspection.
(Watch at left)
"We say that occupation should be done away with," said Ahmadinejad. "Warlike behavior should be done away with. Terrorism should be done away with. The killing of women and children should be done away with. Has the Zionist regime done anything other than this during the last 65 years? No, they haven't."