(U.S. Navy photo by Chandler Harrell)

About 5,000 U.S. troops are sailing toward the Middle East with an F-35B detachment, marking the first time the American Joint Strike Fighters are likely to conduct real-world combat operations.

Sailors and Marines with the Essex Amphibious Ready Group and 13th Marine Expeditionary Unit left San Diego in July 2018 for a six-month deployment to the Middle East and Western Pacific. The three-ship ARG includes the amphibious assault ship Essex, amphibious transport dock Anchorage and dock landing ship Rushmore.


The 13th MEU includes an F-35B detachment from Marine Fighter Attack Squadron 211, based out of Yuma, Arizona.

"This is the newest and most lethal aircraft that the Joint Force has, and the fact that it's coming into the [U.S. Central Command] theater and potentially seeing some combat operations is a big deal," Lt. Col. Jaime Macias, chief of plans at Marine Corps Forces Central Command, said in a Marine Corps news release leading up to the deployment.

ARG-MEU deployments are typically publicized by the Defense Department, but this one — the first to leave the U.S. with an F-35 attack squadron detachment — was not. Citing operational security, officials declined to explain the change in policy.

The F-35B Lightning II

(U.S. Marine Corps photo)

"The Essex Amphibious Ready Group with embarked 13th Marine Expeditionary Unit got underway from San Diego, July 10, 2018," Lt. Tim Gorman, a U.S. Pacific Fleet spokesman, said in a statement. "For reasons of operational security, we are not publicly disclosing any additional details."

USNI was the first to report on the ARG-MEU's quiet departure. Members of the MEU this one is set to replace were sent into Syria earlier this year to fight the Islamic State, The Washington Post reported.

The sailors and Marines conducted a six-month-long certification process before departing. The team is ready to respond to crises that erupt during their deployment, according to a Marine Corps video about the workup.

The Marine Corps' variant of the Lightning II stealth jet is designed for sea deployments since it can take off and land vertically.

"Throughout the training, we've seen this platform increase our ability to gain a foothold for our operations," the video states. "This is the most capable aviation platform to support our riflemen on the ground."

In addition to the F-35 detachment, the MEU also includes Battalion Landing Team 3rd Battalion, 1st Marines; Combat Logistics Battalion 13; Marine Medium Tiltrotor Squadron 166; and a command element.

This marks the second time in four months that the F-35B has deployed aboard a Navy ship. In March 2018, members of the Japan-based Marine Fighter Attack Squadron 121 patrolled the Pacific from aboard the amphibious assault ship Wasp.

The East Coast-based Iwo Jima ARG and 26th MEU are slated to wrap up a Middle East deployment in August 2018 as these Marines and sailors move in.

This article originally appeared on Military.com. Follow @military.com on Twitter.