WASHINGTON — A U.S. Army proposal to hand over development and procurement responsibility of the Patriot air and missile defense system to the Missile Defense Agency (MDA) would not adversely affect the program, the MDA’s top official told lawmakers May 26.

The Defense Department has yet to decide whether to move Patriot and the Integrated Air and Missile Defense Battle Command System — or IBCS — to the MDA’s purview, Army Lt. Gen. Patrick O’Reilly, the MDA’s director, said during a hearing of the Senate Appropriations defense subcommittee.

The MDA currently develops and procures the majority of the Pentagon’s ballistic missile defense systems, including the Army’s Terminal High Altitude Area Defense system. The Army requested $877.1 million in 2012 for development and procurement of the Patriot Advanced Capability-3 system and the next-generation Missile Segment Enhancement interceptors, both of which are developed by Lockheed Martin Missiles and Fire Control of Dallas. The Army requested $270.6 million in 2012 for the IBCS program being developed by Northrop Grumman Information Systems of Reston, Va.

Sen. Richard Shelby (R-Ala.) asked whether the budget for Patriot and IBCS would be protected if they become a part of MDA’s portfolio.

O’Reilly said the Patriot and IBCS money would be safe. “[W]e have very closely coupled budget development processes that have been established by the deputy secretary of defense between MDA and the services,” he said. “So the Army does review and we actually build our budgets together before we submit them to [the Office of the Secretary of Defense], and then they’re reviewed by the Joint Chiefs and others to ensure that there is a prioritized budget that matches the Army’s needs and the Joint Chiefs’ needs.”

O’Reilly also told lawmakers the MDA is on track to fully field this year the first increment of the so-called Phased Adaptive Approach for European missile defense. The Aegis-equipped USS Monterey is now on station in the Mediterranean Sea, and the AN/TPY-2 forward-based radar will be deployed to Southern Europe by the end of the year, O’Reilly said. The host nation for that sensor has not yet been determined, MDA spokesman Rick Lehner said in a May 26 email.

The capability promised by the first increment of the Phased Adaptive Approach was fully demonstrated in a March flight test in which an operationally configured Aegis ship destroyed an intermediate-range ballistic missile over the Pacific Ocean using cueing from a forward-based radar, O’Reilly said.

The MDA also is on track with the longer-range SM-3 Block 2A missile that is being developed with Japan, O’Reilly said. Engineering work at Mitsubishi Heavy Industries in Nagoya, Japan, was slowed by the earthquake and tsunami that devastated the Japanese coastline in March and caused multiple nuclear power plant accidents. But the two nations should be able to begin flight testing the new interceptor in 2015 in time for a 2018 deployment, O’Reilly said.

Of bigger concern are some of the Japanese foundries that produce focal plane arrays, O’Reilly said.

“They have been affected by their proximity to the nuclear power plant and we are concerned about that,” O’Reilly said, without specifying which plant. “That is an ongoing concern of our reliance on only one or two foundries around the world to produce these focal plane arrays that have wide applications not just for missile defense.”