Israeli Defence Minister Ehud Barak approved in principle on Sunday the purchase of 20 U.S.-built radar-evading stealth fighters in a deal worth $2.75 billion, Israeli defence ministry officials said. According to Reuters, the F-35 warplanes are expected to be delivered between 2015 to 2017, an Israeli defence official said. A ministry statement said Barak "approved in principle the recommendations of the Israel Defence Forces and the Defence Ministry to move ahead" with the purchase. The stealth fighter, made by Lockheed Martin Corp, "will afford Israel continued air superiority and maintain the technological edge in our region", the statement quoted Barak as saying. The defence official said Israel planned to buy initially 20 planes, estimating the total price tag at $2.75 billion, to be covered by an annual U.S. defence grant of $3 billion. Officials predicted final approval of the deal could be given by the end of September by a panel of Israeli government ministers.