The sale by the United States of 20 F-35 fighter jets to Israel poses a threat to security in the Middle East, Syrian Foreign Minister Walid Muallem warned on Friday. 'The agreement to buy F-35 planes signed by Israel seriously threatens stability and security in the region,' Muallem told reporters in Sirte, Libya where Arab foreign ministers were meeting. 'We are told that (Israeli Prime Minister Benjamin) Netanyahu will announce a two-month freeze on settlements, provided this issue is not raised again, and obtain in exchange a deal for very sophisticated arms,' he said. 'The question is no longer a two-month settlement freeze, but rather a threat to Arab security.' Officials in Washington announced on Thursday that Israel signed the contract for the 20 fighter jets after the United States offered 'incentives' for the Jewish state to help sputtering peace talks. 