31 USC 5103
" United States coins and currency (including Federal reserve notes and circulating notes of Federal reserve banks and national banks) are legal tender for all debts, public charges, taxes, and dues. Foreign gold or silver coins are not legal tender for debts. "
31 USC 5119
" the redemption may be made only in gold bullion bearing the stamp of a United States mint or assay office in an amount equal at the time of redemption to the currency presented for redemption. "
Do you see the consecutive like minded rules here ? If it does not have a seal of the united states when exchanged it is not considered a payment on debt. So therefore there is only illusion that debts are being paid for when this should be telling you it don't matter where the ink and paper comes from as long as it bears that seal or the product and service that is licensed by that government or an associate government such as one of the several states.
The same goes for donations to help foreign people in other countries, I doubt you could just send money directly to a family in a foreign country and get a tax break on it, it has to go through a U,S. Corporation, foundation or association to be able to get that tax break.
It could be possible though i guess but you probably get audited later for it if your in the position of acting like a taxpayer filing, wanting a benefit.
Goes back to my explanation of a petty cash box per say in the Treasury of the United States. Accounting books must be balanced at the end of the day or quarter however the entity is setup.