Following a demonstration in February 1951, the Canbera was built under licence in the US by the Glen L Martin Company. Designated B-57, 403 were produced for the USAF. Initially the B-57A had a bubble cockpit like the UK's B.2 but the definitive US version was soon produced with a tandem, opening, fighter style cockpit, a revolving bomb-bay and wing mounted cannon.
Used extensively in Vietnam, variants included RB-57A, EB-57A, B-57B, EB-57B, B-57C, D and E, and the B-57F and G.