WASHINGTON — A substantial proportion of the manufacture of Israel’s Iron Dome batteries will shift to the United States as part of a major increase in US funding for the anti-missile program.

The U.S. Missile Defense Agency last week announced an immediate transfer of $429 million to Israel to fund the program, considered critical in recent years in deflecting short-range rocket attacks from the Gaza Strip.

A condition of the cash infusion is US manufacture of the systems.

“Significantly enhanced levels of co-production by US industry in the United States is a new stipulation under the agreement,” Richard Lehner, a Pentagon spokesman, told JTA in an email Wednesday. “Previously there were only nominal levels of US industrial participation in Iron Dome production.”

The funding is on top of the $3.1 billion Israel receives this year in defense assistance from the United States and is a substantial increase over the $160 million Israel had been asking for the program.