Unit Deployment Program 25.1

A U.S. Marine with 2nd Battalion, 23rd Marines, forward deployed with 4th Marine Regiment, 3d Marine Division as part of the Unit Deployment Program, conducts a live fire range during a patrol during Korea Viper 25.4 at Camp Rodriguez, South Korea, May 22, 2025. Korea Viper is a recurring exercise series that demonstrates the Republic of Korea and U.S. Marine Corps' ability to respond decisively in the region as a singular, unified force while strengthening relationships and trust between the two allies. (U.S. Marine Corps photo by Lance Cpl. Tucker Mocan)

U.S. Marine Corps Staff Sgt. Ezequiel Delatorre, a network chief, with Headquarters and Service Company, 2nd Battalion, 23rd Marines, 4th Marine Division, Marine Forces Reserve, and a native of Oxnard California, counts Marines as they walk into a bus on Marine Air Ground Combat Center Twentynine Palms, California, March 11, 2025.The Marines are headed to Kadena Air Base, Okinawa, Japan as part of Unit Deployment Program 25.1. The activation marks the beginning of an intensive period of training for 2nd Battalion, 23rd Marines as they provide a total force solution in support of the UDP by aligning Marine Forces Reserve’s commitment to Marine Corps strategic objectives. This is first time since 2020 that an entire Reserve infantry battalion has activated to support the Unit Deployment Program. (U.S. Marine Corps photo by Sgt. Scott Jenkins)

U.S. Navy Hospital Corpsman Petty Officer 1st Class Billy Bui, a senior line corpsman with Weapons Company, 2nd Battalion, 23rd Marine Regiment, 4th Marine Division, poses for a photo during an Adversarial Force Exercise at Marine Corps Air Ground Combat Center, Twentynine Palms, California, Dec. 9, 2024. Marines with 2nd Battalion, 23rd Marine Regiment participated in AFX, the primary readiness generating event, prior to their deployment as an opportunity to receive training across all warfighting functions in a realistic and fully resourced environment. This deployment is significant for the Reserve battalion and Reserve force contributing units to support exercises and operations outside of the continental U.S. (U.S. Marine Corps photo by Cpl. Madisyn Paschal)

Fox Company, 2nd Battalion, 23rd Marine Regiment, 4th Marine Division, is part of the first entire Reserve infantry battalion to support a UDP since 1st Battalion, 25th Marine Regiment, deployed in 2020.This deployment is significant for the Reserve battalion, which is spread out across the U.S., and to the Reserve force contributing units to support exercises and operations outside of the continental U.S. The activation marks the beginning of intense training as 2nd Battalion, 23rd Marine Regiment provide a Total Force solution in support of the UDP to align with Marine Forces Reserve’s commitment to the Marine Corps’ strategic objectives while supporting III Marine Expeditionary Force in Okinawa, Japan.