I lied about not commenting. Your comments raise one point I do want to respond to.
You know that as long as you are US citizens, you are subject to US tax laws and owe US tax, no matter where you live. (There are some credits and deductions when you live overseas, but they are still part of the overall tax laws you must follow.)
Gifting the property to your son may not be the best tax strategy. If you gift the property, then his cost basis is whatever you paid, and not the market value at the time or anything else. That affects his tax position if he rents or sells the property, and may subject him to higher US taxes than otherwise. You would want to consult with a professional financial advisor before making that move.
