CENTCOM said it had carried out a new round of defensive strikes in southern Iran, while an Iranian drone attack on the Kuwait airport killed one person.
The U.S. has been "highly successful" in achieving its military objectives in Iran, but the country continues to field a robust drone arsenal, Rubio said.
A tentative deal has been reached to end the war and restart transit in the Strait of Hormuz, and then negotiations on more difficult issues would begin.
By Parisa Hafezi, Angus McDowall and Michael Georgy, Reuters