The Birmingham News, Julie Bennett/AP Photo

Tough talk from Vice President Joe Biden today, warning that the U.S. is determined to keep Iran from obtaining nuclear weapons.

"Big nations can't bluff," said Biden at a meeting of the American Israel Public Affairs Committee (AIPAC), a group that lobbies in favor of Israel. "Presidents of the United States cannot bluff. And President Barack Obama is not bluffing."

Israel's Prime Minister, Benjamin Netanhayu, has repeatedly called for the international community, and the United States, to keep Iran from crossing the "red line," enriching enough uranium to make a nuclear weapon.

The Obama administration has employed a "dual track" strategy on Iran, continuing diplomatic negotiations while imposing harsh sanctions on the regime of President Mahmoud Ahmadinejad. Biden told AIPAC that Iran has a limited time for negotiations.

"We're not looking for war. We're looking to and ready to negotiate peacefully, but all options, including military options, are on the table," he said to a cheering crowd.

In his 40-minute speech he also said the Obama administration's support of Israel is the strongest in the country's history. Biden spoke of how the United States supports the Jewish state militarily, citing the success of the Iron Dome program used in last year's conflict with Gaza, and other missile defense and radar projects currently in progress.

Biden also said America stands up for Israel diplomatically across the globe. He told the crowd that President Obama makes it clear to all other allies that U.S. support for Israel is, and always will be, unwavering.

"There is only one nation, only one nation in the world that has unequivocally, without hesitation and consistently confronted the efforts to delegitimize Israel. At every point in our administration, at every juncture, we've stood up on the legitimacy - on behalf of legitimacy of the state of Israel," said Biden.

Wherever Obama goes in the world, said Biden, "he makes clear that although we want better relations with Muslim- majority countries, Israel's legitimacy and our support for it is not a matter of debate… It's simple, and he means it. Do not raise it with us. It is not negotiable."

Biden joked about his envy at President Obama's trip to Israel later this month.

"I'm a little jealous that he gets to be the one to say 'this year in Jerusalem', said Biden, drawing laughter and cheers. " But I'm the vice president. I'm not the president," he shrugged, smiling.

"So when I told him that. I'm not sure he thought I was serious or not."