US F-35 fighters fly first ever combat mission

American F-35 stealth fighters have been used in a combat operation for the first time, a defense official said, marking a major milestone for the most expensive plane in history.

Thursday's mission took place against Taliban targets in Afghanistan's Kandahar province, when more than one F-35 flew from the USS Essex amphibious assault ship.

"It was a successful strike," the official told AFP.

The planes deployed were the F-35B variant, used by the Marine Corps and capable of taking off from a short runway and landing vertically. The Israeli military said in May that it had used its newly acquired F-35s in combat operations, becoming the first country to do so.

Launched in the early 1990s, the F-35 is considered the most expensive weapons system in US history, with an estimated cost of some $400 billion and a goal to produce 2,500 aircraft in the coming years. Once servicing and maintenance costs for the F-35 are factored in over the aircraft's lifespan through 2070, overall program costs are expected to rise to USD 1.5 trillion.

Proponents tout the F-35's radar-dodging stealth technology, supersonic speeds, close air support capabilities, airborne agility and a massive array of sensors giving pilots unparalleled access to information.

But the program has faced numerous delays, cost overruns and setbacks, including a mysterious engine fire in 2014 that led commanders to temporarily ground the planes.