The US is almost certainly encouraging other countries to donate their F-16s to Ukraine in exchange for buying F-35s at a discount. This has a ton of benefits. It generates new sales (both today and in the future via maintenance contracts) for US produced equipment, it gets Ukraine much-needed lethal aid, and it upgrades the air force of various NATO countries.
The US is almost certainly encouraging other countries to donate their F-16s to Ukraine in exchange for buying F-35s at a discount. This has a ton of benefits. It generates new sales (both today and in the future via maintenance contracts) for US produced equipment, it gets Ukraine much-needed lethal aid, and it upgrades the air force of various NATO countries.