"The purpose of the Jewish state is to secure the Jewish future," he said. "That is why Israel must always have the ability to defend itself, by itself, against any threat."
Despite two speeches and public remarks in the Oval Office, it remained far from clear that Mr Obama and Mr Netanyahu had bridged the significant gap between them. Contrary to some expectations, the Israeli leader made no public demand nor private demands for "red lines" that would trigger an American attack on Iran but nor did he offer any support for Mr Obama's non-military efforts.
In his speech, he drew a pessimistic time line of the attempts to peacefully deter Iran's nuclear ambitions, saying the international community had tried diplomacy for a decade and sanctions for six years without success.
"I appreciate President Obama's recent efforts to impose even tougher sanctions against Iran. Those sanctions are hurting Iran's economy. But unfortunately, Iran's nuclear march goes on," he said.
In the most emotive section of a speech given to an audience that included half of the US Congress as well as members of Mr Obama's cabinet and some 13,000 delegates, Mr Netanyahu drew comparisons with America's unwillingness to bomb the Nazi concentration camp at Auschwitz.
Brandishing a copy of a 1944 letter from the US Department of War, he recounted how the Allies had refrained from attacking the camp out of fear it might provoke "even more vindictive action" from the Germans.
"My friends, 2012 is not 1944... Never again," he cried, repeating one of the founding slogans of Israel to a roaring standing ovation from the audience.
The prime minister, himself a former commando, used the speech to lay out the justifications for a possible Israeli attack that would undoubtedly draw fury from Islamic nations around the world.
"There's been plenty of talk recently about the costs of stopping Iran. I think it's time to talk about the costs of not stopping Iran," he said, claiming that a nuclear Iran would trigger an arms race in the Middle East and allow the regime to choke off the world's supply.
"The worst nightmare of all," he said, was the prospect of nuclear terrorism in which an Iranian bomb could be smuggled into an American or Israeli city.
Linking the US's fate with that of his own country, he said: "For the sake of our prosperity, for the sake of our security, for the sake of our children, Iran must not be allowed to get nuclear weapons."
He also sought to minimize the differences between himself and Mr Obama.
"(Mr Obama) stated clearly that all options are on the table and that American policy is not containment," Mr Netanyahu said.
"Israel has exactly the same policy. We're determined to prevent Iran from developing nuclear weapons, we leave all options on the table and containment is definitely not an option."
During a two-hour meeting earlier on Monday, the two leaders, who have a famously testy relationship, made clear their mutual concerns over Iran.
In an impassioned on-camera statement during that meeting, Mr Netanyahu told Mr Obama: "Israel must have the ability always to defend itself, by itself, against any threat.
"That's why my supreme responsibility as prime minister of Israel is to ensure that Israel remains the master of its fate."
Mr Netanyahu is due to meet wtith US Secretary of State Hillary Clinton and visit the US Congress on Tuesday.