Afaik there's a term for sending money abroad to family but I can't remember it's name.
Remittances?
My assumption would be it's the same as standard currency. If you can transfer via PayPal, western union or a bank account then you should be able to do it with bitcoin.
But that's standard fiat though?
If not, how are the irs going to know about it? Are you planning to transfer large amounts as this could be where a dex might be useful if they'd want to break the link between sending to a sanctioned country from theirs.
Unless you declare it, then IRS wouldn't know in the beginning,
If you can't find any answers then you should consider sending money from US to a sanctioned nation is illegal and it's potential consequences.