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 Kuwaiti Army said in a post to X on Thursday morning that its air defenses were "responding to hostile missile and drone threats."
Iran's Islamic Revolutionary Guard Corps said in a statement on Thursday that it attacked the U.S. airbase from which American forces launched strikes on Bandar Abbas.
"This response is a serious warning to the enemy that any act of aggression will not go unanswered, and if repeated, our response will be even more decisive," the IRGC said in the statement, which was carried by the state-owned Press TV channel's Telegram account.
"The aggressor bears full responsibility for the consequences," the IRGC added.
-ABC News' Morgan Winsor
The U.S. carried out new airstrikes in southern Iran, shooting down four one-way attack drones that posed a threat around the Strait of Hormuz and then a ground control site, a U.S. official said.
The official said U.S. forces struck an Iranian ground control station in Bandar Abbas that was about to launch a fifth drone.
The official called the strikes "measured, purely defensive, and intended to maintain the ceasefire."
This is the second time in three days that the U.S. has carried out self-defense strikes against Iranian military targets in southern Iran.
On Monday the U.S. carried out airstrikes against Iranian missile locations and boats that U.S. Central Command said were preparing to launch mines in the Strait of Hormuz.
-ABC News' Luis Martinez
Speaking at a cabinet meeting on Wednesday, President Donald Trump said the Iranians "want very much to make a deal," but an agreement hasn't been reached yet.
"We're not satisfied with it, but that we will be. Either that or we'll have to just finish the job," Trump said.
"Iran cannot have a nuclear weapon. I'm doing that for the world. I'm not doing it just for us," Trump said.
