This isn't going to happen. It's a logistical nightmare, and more importantly, it would be a clear violation of the Constitution, and judicial precedent. The government has to guarantee the constitutional rights of anyone incarcerated, and they can't do that if the inmates are being housed in a prison in a 3rd world nation where constitutional rights don't exist. I also believe it would run afoul of the 8th Amendment prohibition on cruel and unusual punishment.

And then there's the labor issue. This would put a whole lot of American prison staff out of a job, and reduce the inmate housing numbers which the prison industrial complex would go apeshit over. Because privately managed prisons get paid per inmate. And those prison lobbyists are really tight with Congressional Republicans. Ultimately, making this work would be a total nightmare and cause a lot of problems, including push back from Republican lawmakers who take lobbying money from the prison people. I don't see it happening.