The Air Force declared Tuesday that the much-criticized F-35 Joint Strike Fighter has achieved "initial operational capability," meaning that if it's needed, it could be sent to war.

The announcement was made by Gen. Hawk Carlisle, the commander of Air Combat Command at the Pentagon.

"It is the initial combat capability, and what that means is if a combatant commander comes to the United States Air Force, and asks for a capability that the F-35 has, I would deploy it in support of operations," said Carlisle.

The Air Force version of the plane, the F-35 "A" model, takes off and lands conventionally, unlike the Marine version which can hover and land vertically, and the Navy variant which is designed to catch a tailhook on a carrier.

The F-35A, named "Lightning II" and produced by Lockheed Martin, is a fifth-generation stealth fighter aircraft that was 15 years in the making, and was years behind schedule and some $200 billion over budget. It's been called the world's most expensive weapons program, and a Pentagon boondoggle.

But Carlisle said the airplane is performing well and said recent tests involving dropping bombs and firing air-to-air missiles were successful, including one test in when it shot down a drone.

While it's a pricy fighter, Carlisle says the cost per plane is coming down into the $80 to $85 million range, which is comparable to fourth generation fighters like the F-22.

"With this airplane, you are going to get an order of magnitude better capability with respect to its ability to penetrate airspace that other airplanes cannot penetrate," he said.

Senate Armed Services Committee Chairman John McCain issued a qualified endorsement of the F-35A calling the achievement of initial operational capability an "important milestone," but noted the plane's troubled acquisition history.

"For the most expensive weapons system in history, the road ahead remains long," McCain said. "The Senate Armed Services Committee will continue to exercise rigorous oversight of the Joint Strike Fighter program's long-delayed System Development and Demonstration phase as well as the start of the operational test and evaluation phase."

The Air Force currently has 15 operational aircraft based at Hill Air Force Base, Utah.