The UK has proposed an F-35 joint strike fighter (JSF) aircraft exchange with the US, according to a Pentagon letter to US Congress.

Under the proposal, the UK will receive one US F-35 aircraft variant (F-35C) in exchange for a short take-off and vertical landing (STOVL) version, the F-35B.

The proposal also stipulates that the UK would cover related costs to upgrade of its F-35B aircraft to US requirements and will also be responsible for any unique requirements for the F-35C.

The Pentagon has already requested a legislative amendment to the proposed trading agreement in the 2012 defence authorisation bill.