U.S. President Donald Trump has appeared at a ceremony in New York on Monday to sign a national defence bill that will prevent U.S. weapons sales to Turkey, including the new generation F-35 fighter jets ordered by the country. The $716 billion John S. McCain National Defense Authorization Act for Fiscal Year 2019 (NDAA) calls a halt to weapons sales to Turkey until the Pentagon produces a report within 90 days detailing U.S.-Turkish relations and the effect of cutting Turkey out of the F-35 production chain. Turkey received its first pair of a projected 100 aircraft in June. The jets remain in the US while their Turkish pilots receive training. Delivery will not take place before September 2019. The removal of Turkey from the F-35 supply chain would be a blow for Turkish defence firms, at least ten of which are involved in production of components including fuselages and cockpit screens. Turkey has reportedly invested over $1 billion in the F-35 project.