Lockheed Martin's F-35 fighter jet will drop weapons and take part in a major U.S. military exercise this week for the first time, another milestone for the Pentagon's most expensive weapons program, Air Force officials said Monday.

The exercise, called "Green Flag West," tests the U.S. military's ability to engage in air-to-surface conflicts and helps get ground troops who pinpoint potential air strikes ready for combat.

The three F-35 Lightning II variant aircrafts (F-35 A, B, and C) are designed and manufactured in Lockheed Martin's massive Fort Worth, Texas plant. Several F-35 A-model jets, along with a host of other warplanes and other weapons, will participate in the exercises.

General Herbert Carlisle, commander of Air Combat Command, told Reuters that exercises were an important way to expose weapons and pilots to more real-world battle scenarios.

"It's incredibly important that you've got to get past just the theoretical ... to get it into the fog and friction of dynamic environment that is changing rapidly," Carlisle said after an event hosted by the Air Force Association.

The Air Force has used aircraft equipped with F-35 sensors in past exercises, but this will be the first time that more "operationally representative" aircraft take part, he said.

Two F-35B aircraft fly in formation over Edwards Air Force Base, Calif., in September 2013. Lockheed Martin Carlisle said the Air Force was still working through some problems with how data from various radars and other sensors are fused and displayed to the pilot, but he expected the aircraft to perform well in the exercise.

"The airplane's pretty impressive," Carlisle said. He said the jet's radar-evading capabilities and large number of sensors would help improve the performance of all other U.S. aircraft in a fight, much like the F-22 does now.

The Marine Corps is expected to declare an initial squadron of 10 F-35B jets ready for initial combat use in July, with the Air Force to follow suit in August 2016.

The fifth Lockheed Martin F-35B Lightning II Short Take Off/Vertical Landing flight test aircraft delivered to the Marine Corps arrives at Naval Air Station (NAS) Patuxent River, Md., Liz Kaszynski/Lockheed Martin Meanwhile, the Pentagon has proposed a plan to US lawmakers to approve a purchase of 57 F-35s for a cool $11 billion within the next fiscal year, Military.com reports.

The $400 billion and counting F-35 program has so far delivered 140 of the anticipated 2,443 jets to the US Department of Defense and five aircraft to foreign military buyers.