There are three levels of international participation. The United Kingdom is the sole 'Level 1' partner, contributing slightly over US$2 billion, about 10% of the development costs. Level 2 partners are Italy, which is contributing US$1 billion, and the Netherlands, US$800 million. At Level 3 are Canada, US$440 million; Turkey, US$175 million; Australia, US$144 million; Norway, US$122 million; and Denmark, US$110 million. The levels generally reflect the financial stake in the program, the amount of technology transfer and subcontracts open for bid by national companies, and the priority order in which countries can obtain production aircraft. Israel and Singapore have also joined as Security Cooperative Participants.Schnasi, Katherine V. "Joint Strike Fighter Acquisition: Observations on the Supplier Base." US Accounts Office. Retrieved 8 February 2006. Due to delays in development and testing, the introduction date of the F-35 was gradually pushed from 2010 to 2015.
