Vice President Joe Biden touted the successes of the Iranian nuclear deal Sunday to a pro-Israel policy group that loudly advocated against the deal as it went through Congress.

"Last year at this time there was only one topic on everyone's mind, a nuclear deal," Biden told a crowd of over 18,000 people at the annual American Israel Public Affairs Committee policy conference in Washington. "This year we're no longer dealing with hypotheticals."

This was Biden's first time speaking to AIPAC since the agreement between the United States, five other world powers and Iran was finalized in June 2015. Under the deal the United States, European states and the United Nations ended economic sanctions on Iran in exchange for the longtime rogue state agreeing to end a nuclear weapons program and accept inspections aimed at verifying compliance.

Israeli Prime Minister Benjamin Netanyahu and AIPAC opposed the deal, arguing it would hurt Israel's security.

Biden's description of the Obama administration's deal with Iran left what was once a thunderously loud room quiet.

"What we said all along still holds. If Iran violates the deal, the United States will still act. We'll act. Our commitment is unshakeable," Biden said to scattered applause.

Many pro-Israel hawks in the United States have criticized the enforcement of the deal. Many critics complained the agreement made peace with a proponent of terror in the Middle East.

"Those sanctions remain in place and we are enforcing them vigorously," Biden said, a few days after meeting with Netanyahu and President Reuven Rivlin in a trip to Israel.

Democratic presidential candidates Hillary Clinton and Bernie Sanders support the nuclear deal. GOP candidates oppose and have all vowed to overturn the agreement.

Biden, speaking while President Obama made a historic visit to Cuba, offered standard affirmations of the United States' close ties to the Jewish state.

"Israel is stronger and more secure today because of the Obama-Biden administration," Biden said. "Period."