The U.S. flew two bomber jets over the Persian Gulf on Thursday, according to a statement from the U.S. Central Command. “We want to ensure that if they are contemplating some sort of an aggressive act, that they would think twice about it before they did it,” an anonymous military official told NBC News. President-elect Joe Biden has called for diplomacy with Iran, looking to restore the 2015 deal that lifted sanctions on the nation while mandating that it not create a nuclear weapon. Since President Trump pulled out of the deal in 2018, the U.S. and its allies have acted aggressively toward Iran. In January, a U.S. drone strike in Baghdad killed Qassem Soleimani, the nation’s top general. In November, Mohsen Fakhrizadeh—who ran Iran’s nuclear program before it was officially disbanded in 2003—was assassinated, with both U.S. and Iranian officials claiming Israel was behind the killing, according to CNN.