The United States will give Israel $US38 billion ($A51 billion) in military aid over a decade, the largest such aid package in US history, under an agreement disclosed and signed this week.
The deal, whose details were reported by Reuters earlier, will allow Israel to upgrade most of its fighter aircraft, improve its ground forces' mobility and strengthen its missile defence systems, a top US official said.
While the package constitutes the most US military aid ever given to any country, it entails concessions by Israeli Prime Minister Benjamin Netanyahu, according to officials on both sides.
Those include Israel's promise not to seek additional funds from Congress beyond what will be guaranteed annually in the new package, and to phase out a special arrangement that has allowed Israel to spend part of its US aid on its own defence industry instead of on American-made weapons, the officials said.
The $US38 billion memorandum of understanding covers US fiscal years 2019-2028 and succeeds the current $US30 billion MOU signed in 2007, which expires at the end of fiscal 2018.
"Prime Minister Netanyahu and I are confident that the new MOU will make a significant contribution to Israel's security in what remains a dangerous neighbourhood," US President Barack Obama said in a written statement.
The agreement was signed on Wednesday at the State Department by US Undersecretary of State Thomas Shannon and by Jacob Nagel, acting head of Netanyahu's national security council.
