Pub. L. 90-249, tit. I, sec. 119

Sec. 119. The President is directed to withhold economic assistance in an amount equivalent to the amount spent by any underdeveloped country other than Greece, Turkey, Iran, Israel, the Republic of China, the Philippines, and Korea for the purchase of sophisticated 81 Stat. 941weapons systems, such as missile systems and jet aircraft for military purposes from any country, unless the President determines that such purchase or acquisition of weapons systems are vital to the national security of the United States and reports within thirty days each such determination to the Congress.