Remove the aid the U.S. sends to those nations for every rejection we reduce monies we send there or if anyone is refused all aid is frozen until such time they accept their own people back.
That is a good question Sox, that had me think Start a new Country. A United Nations protectorate or alike. Could be a good money maker for co's building out the infrastructure. People could build their own homes and agriculture and other industry to help offset costs. If a reserve/preserve on an existing Country - they can collect rent.