US President Barack Obama's administration has approved $250m in military aid towards Israel's advanced anti-rocket system, the Iron Dome.
The US House of Representatives made the decision after it passed a continuing resolution regarding funds for the 2011 fiscal year.
US House Representative Steve Rothman said it is the first funding of its kind for the short-range rocket and artillery shell defence system.
"This funding sends a strong message, to both our enemies and allies, by providing more total dollars than ever before toward these rocket and missile defence programmes," Rothman said.
The US Ministry of Defense, however, is still considering the balance between the number of radars for the systems and the number of intercept missiles, which cost $40,000 each.
Israel completed tests on its Iron Dome system in January and the next phase is to integrate the system into the army.
The funds are in addition to more than $200m already allocated for the joint US-Israel anti-missile systems, David's Sling and Arrow.