@user17574520943 very much agreeing with my colleague @Opus 17 for his analysis and suggestions for reporting of this transaction, would just like to add
(a) assuming the monies would be wired to your own US bank account, the bank would raise a SAR ( Suspicious Activity Report ) as a matter of course. Nothing usually happens to these but a record exsits at the US treasury.
(b) By recognizing the whole amount as a "gift" from a foreign person on form 3520 you would close any questions that may arise in future. This also protects you in case and in the distant future you are not required to return the amount to the NRA.
(c) While no reporting would be required of you in future when you return the loaned amount, tagged as gift, there should be no SAR issue since again a SAR would be raised. There is nothing wrong or illegal about returning a gift ( never mind the size of the gift ).
For all these reasons I think the cleanest way to establish a trail is to recognize this as gift by raising the form 3520 --- note this does not go with your return ( see the IRS instructions on form 3520 ---> Form 3520 (Rev. December 2023) and is to be filed during the year wherein the amount was received.
