The United States plans to expand its THAAD missile defense force to seven batteries by 2019 from the current four, a top military official in charge of missile defense has said.

Lt. Gen. David Mann, commander of the Joint Functional Component Command for Integrated Missile Defense, unveiled the plan in written testimony submitted Thursday for a hearing of the House Armed Services Committee's Strategic Forces Subcommittee.

"There are now four activated THAAD batteries. Equipment training and fielding has been completed for three of the batteries. In April 2013, one of these batteries conducted the first-ever operational deployment of THAAD in response to the escalation of tensions in the Pacific region," the commander said.

"The fourth THAAD battery is currently undergoing training and will be operationally available next year. A fifth battery is scheduled to become fully operational the following year. By 2019, the THAAD force is scheduled to consist of seven batteries," he said.

One of the four batteries has been deployed to Guam to defend against North Korean ballistic missile threats. The U.S. also wants to deploy another THAAD battery to South Korea, where 28,500 American troops are stationed to deter the communist nation.

South Korea has been badly divided over whether to allow such a deployment, with supporters saying the deployment would help better protect against North Korea's ballistic missile threats, and opponents claiming it would inflame tensions with China and Russia.

The issue has become one of the most sensitive defense and political issues in the South.

Mann said that THAAD, which stands for Terminal High Altitude Area Defense, is designed to defend deployed and allied forces, population centers, and critical infrastructure against short and medium-range ballistic missiles.

"The addition of THAAD capabilities to the Army's air and missile defense portfolio brings an unprecedented level of protection against missile attacks to deployed U.S. forces, partners, and allies," the commander said.

A fully operational THAAD battery consists of 95 soldiers, an AN/TPY-2 radar, six launchers, a fire control and communications element, a battery support center, and a support element, he said.

"THAAD has a unique intercept capability in both the endo- and exoatmosphere using proven hit-to-kill technology," he said.

The commander also said that a new training facility, which enables virtual training for the soldiers who will operate the THAAD system, recently opened at Fort Sill, Okla.

James Syring, director of the Missile Defense Agency, also said in his written testimony for the hearing that his agency accelerated procurement of THAAD Battery 7 for delivery in fiscal year 2017 in order to meet the demand from combatant commanders.

The official also said that the agency has requested $464.1 million for THAAD procurement in next year's budget, including the purchase of 30 THAAD interceptors and procurement of training devices for Fort Sill.

By the end of fiscal year 2016, MDA will deliver an additional 48 THAAD interceptors to the Army, for a total of 155 interceptors, he said. (Yonhap)