The U.S. Department of Defense abandons plans to buy Israeli-made missile defense systems due to cyber vulnerabilities and other problems. according to The Times of Israel.

The Israel-based, English-language online newspaper has reported that U.S. military curbing its plans to adopt the Iron Dome missile defense system due to concerns about its compatibility with existing US technologies, scrapping its plans to buy two more batteries.

A central problem was Israel’s refusal to provide the U.S. military with Iron Dome’s source code, hampering the Americans’ ability to integrate the system into their air defenses.

Gen. Mike Murray, head of Army Futures Command, said the service identified a number of problems — including cyber vulnerabilities and operational challenges — during efforts last year to integrate elements of Iron Dome with the US Army’s Integrated Battle Command System.

“It took us longer to acquire those [first] two batteries than we would have liked,” Murray told the House Armed Service tactical air and land forces subcommittee on Thursday. “We believe we cannot integrate them into our air defense system based on some interoperability challenges, some cyber challenges and some other challenges.”

Last year, U.S.’s military magazine, Defense News, quoting the deputy in charge of the service’s air and missile defense modernization efforts, has announced that the contract to purchase two Iron Dome batteries for the U.S. Army’s interim cruise missile defense capability has been finalized.

“Now that the contract is set in stone, the Army will be able to figure out delivery schedules and details in terms of taking receipt of the systems,” Daryl Youngman told Defense News at the Space and Missile Defense Symposium in Huntsville, Alabama, on Aug. 8.

The Iron Dome is the world’s most-used system, intercepting more than 1,900 incoming targets with a success rate exceeding 90 percent since being fielded in 2011.

Iron Domedetects, assesses and intercepts a variety of shorter-range targets such as rockets, artillery and mortars. It is effective day or night and in all weather conditions including low clouds, rain, dust storms and fog. It features a first-of-its-kind multi-mission launcher designed to fire a variety of interceptor missiles.

The system can protect deployed and maneuvering forces, as well as the Forward Operating Base (FOB) and urban areas, against a wide range of indirect and aerial threats.