President Trump appeared to suggest the U.S. will resume testing nuclear weapons for the first time in three decades, saying it would be on an "equal basis" with Russia and China.
Known as the Joint Comprehensive Plan of Action, or JCPOA, the deal followed two years of negotiations during the Obama administration.
The world is waiting for President Donald Trump's decision on whether the U.S. will join Israel in military action to wipe out Tehran's nuclear facilities.
Israel launched an expanded assault on Iran on Sunday while Tehran unleashed a fresh barrage of missiles.
The Israeli military strikes on Iran targeted key military leaders with the Islamic Revolutionary Guard Corps and scientists involved with their nuclear program.
The U.S. is assisting Israel in shooting down missiles targeting the country, a U.S. official confirmed to ABC News.