is it not true that the UK government agreed to assist the USA in this field by giving them (I believe) technology from the Derwent engine
GE's work on turbochargers made them the natural industrial partner to develop jet engines when Frank Whittle's W.1 engine was demonstrated to Hap Arnold in 1941. He requested, and was given, the plans for the aircraft's powerplant, the Power Jets W.1, which he took back to the U.S. He also arranged for an example of the engine, the Whittle W.1X turbojet, to be flown to the U.S in October 1941 in the bomb bay of a USAAC Consolidated B-24 Liberator, along with drawings for the more powerful W.2B/23 engine and a small team of Power Jets engineers. A production license was arranged in September, and the W.1 test engines shipped to the US for study were converted to US manufacture as the I-A. The first US jet to fly being the Bell P-59 Airacomet. GE quickly started production of improved versions; the I-16 was produced in limited numbers starting in 1942, and the much more powerful I-40 followed in 1944, which went on to power the first US combat-capable jet fighters, the P-80 Shooting Star.