cash and carry
Roosevelt had his hands tied by the Neutrality Act, but he knew very well that, eventually, the United States would be drawn to war and he also clearly knew which side his citizens will fight on. The Neutrality Act however could be interpreted is such a manner that he could assist the side he chose to assist between the belligerent nations as long as the assistance was paid for.
With this subterfuge the policy of Cash and Carry was implemented. Great Britain received ample supplies from the US, however the British could not be delivered and were constrained to sail across the Atlantic to collect the goods taking all the risks of the submarine warfare waged by the Germans on their not so broad shoulders at the time. All goods however were not paid in cash. A strict account was kept by the bookkeepers and, at the end of the war, the bill was delivered to Chancellor of the Exchequer.
Britain paid by granting leases (often military leases) for American bases to be built overseas on its far and wide imperial archipelagoes.
When I was a student, back in the ’60s, I did part of my research work on the island of Ascension on the South Atlantic. Ascension is a British territory. Most of the island however is still occupied by an American military base obtained under the Cash and Carry policy.