The United States and Israel signed on Thursday a formal agreement under which Washington will provide it with $30 billion in defence aid over the next decade, a 25 percent increase over previous years.

At a signing ceremony in Jerusalem, U.S. Undersecretary of State Nicholas Burns pledged the United States would help Israel maintain a military advantage over its regional foes.

"Needless to say, given Israel's predicament, living in a region that is very violent and unstable, its military edge is of interest to our country, and we've committed to that," Burns said.

"And I think that principle runs through everything that we've done and the agreement that we've signed today."

The United States, Burns said, considers "this $30 billion in assistance to Israel to be an investment in peace, in long-term peace -- peace cannot be made without strength".

The Bush administration said last month it would offer weapons packages worth $20 billion of dollars to Saudi Arabia and other Gulf states over 10 years. Egypt will also get $13 billion in defence assistance, similar to present levels.

The military assistance is designed to reassure Sunni Muslim Gulf nations of Washington's commitment to the region despite its problems in Iraq, as well as to strengthen them in the face of the growing influence of Shi'ite Iran in the area.