The United States and Israel have agreed on a record $38 billion package of U.S. military aid and will sign the pact on Wednesday, enshrining defense funding for Washington's closest Middle East ally for the next decade, officials said.

The deal will represent the biggest pledge of U.S. military assistance made to any country but also involves major concessions from Israeli Prime Minister Benjamin Netanyahu, according to officials on both sides and U.S. congressional aides.

Those include Israel's agreement not to seek additional funds from Congress beyond what will be guaranteed annually and to phase out a special arrangement that has allowed Israel to spend part of its U.S. aid on its own defense industry instead of American weapons, the officials said.