The Hezbollah commander, Ali Musa Daqduq, was killed in an airstrike.
President Donald Trump announced "major combat operations" against Iran on Feb. 28, with massive joint U.S.-Israeli strikes targeting military, government and infrastructure sites.
Following the announcement of a two-week ceasefire, initial U.S.-Iran talks in Pakistan in April failed to reach a peace deal.
Trump later announced the open-ended extension of the ceasefire and the continuation of a U.S. blockade until negotiations are concluded "one way or the other."
The U.S. has intercepted Iranian missiles fired in the region overnight but at the moment there does not appear to have been any major damage or impacts at U.S. facilities, according to a U.S. official.
-ABC News' Luis Martinez
U.S. military strikes against Iran on the second night in a row have been completed, U.S. Central Command said.
In a statement, CENTCOM said U.S. forces "completed additional self-defense strikes against multiple targets," including against Iranian military surveillance capabilities, communication systems and air defense sites.
The statement went on to say: "U.S. Marine Corps, Air Force, and Navy assets fired precision munitions on Iranian targets that posed a threat to U.S. forces and international commercial ships transiting regional waters. The strikes are in response to Iran's unwarranted and continued aggression. U.S. forces remain vigilant, lethal, and ready."
U.S. Central Command is denying Iran's claim that the Strait of Hormuz is closed, saying that commercial ships continue to transit in and out of the waterway.
Iran vowed to "give a crushing and decisive response" to the U.S. strikes, according to Iran's Fars News Agency state media.
