More than 40,000 illegal alien criminals from 79 different countries are housed in federal prisons – costing taxpayers millions every year.
The International Prison Transfer program should help to alleviate the problem as it permits willing criminals to transfer back to their country’s prison system. That could be at least a partial solution, but the problem is that many countries simply refused to accept the transfers – and there are no enforcement measures within the treaty.
See Page 2:

Too bad. Air drop them at the Guatemalan border
If Mexico doesn’t want to take back their criminals, just fly them over Mexico and push them out the door, problem solved.
so we should pay for them?
Use parachutes
B******t dump their$#%&!@*in Mexico and forget about them!
Make them swim back
Tooooooo bad. Here they are.
Exactly–that will solve it and quick!!!
Don’t ask ! Dump them out ! That is what they did to us ! They sent the poorest, criminals, drug cartels, human traffickers, etc. & didn’t ask us if it was , okay ! Who cares if they don’t want them ! Since when do they get a choice, they are their citizens, not ours !
they don’t have a choice