The amendments were passed by the US House of Representatives on 19 June but not without changes that now limited exchanges of nuclear weapons data to nations that had made substantial progress in the field. The same restriction applied to the actual transfer of non-nuclear components of nuclear weapons. American nuclear weapons were to remain under US custody and could not be turned over to allies except in wartime. The sale of nuclear reactors for submarines and nuclear fuel for them and other military reactors was permitted. Only the UK qualified as a nation that had made substantial progress. The bill passed Congress on 30 June 1958 and was signed into law by Eisenhower on 2 July 1958.