Washington: Israel has made an initial request for its annual US defence aid to increase to as much as $US5 billion ($7 billion) when its current aid package, worth an average $US3 billion a year, expires in 2017, US congressional sources have said.

Israel wants $US5 billion per year in military aid for 10 years, for a total of $US50 billion, the congressional aides said on Wednesday. It has been signalling that it wants more money to counter threats it says will arise as a result of the international agreement on Iran's nuclear program, which Israel's government has staunchly opposed.

Israeli security troops take positions at the scene of a stabbing attempt in Hebron on Sunday. Credit:AP

Congressional and other US officials cautioned that negotiations on the new aid deal were still in the early stages and the proposal is not yet at the stage where it has been formally brought to Congress, which must approve the funds.