President Donald Trump was continuing his overhaul of the United States’ immigration practices and policies Tuesday, readying several new actions that will fundamentally transform how the nation processes undocumented immigrants and deportation cases.

As the new White House prepared to radically increase immigrant detention rates along the U.S.-Mexico border, Trump has a plan for migrants and asylum-seekers from countless Latin American migrants will eventually be deported to, regardless of their nationality: Mexico.

Department of Homeland Security memos, signed by Secretary John Kelly and obtained by ProPublica Sunday, revealed the administration plans to tackle Trump’s campaign promise of deporting up to three million undocumented immigrants after taking office by sending them back "to the foreign contiguous territory from which they arrived," instead of their native-nations.

RTSZI20 People participate in a protested against President Donald Trump's immigration policy and the recent Immigration and Customs Enforcement (ICE) raids in New York City on Feb. 11, 2017. Photo: Reuters

The paired implementation memos were issued to Department of Homeland Security employees Tuesday morning.

"This is immigration enforcement under Trump: due process, human decency, and common sense are treated as inconvenient obstacles on the path to mass deportation," the ACLU said in a statement emailed to International Business Times Tuesday.

Under Trump's immigration policies, hundreds of thousands of migrants who make the back-breaking journey from countries including Brazil, Guatemala, Ecuador, Haiti and Honduras will be deported to Mexico, where they would be left without any means of returning to their homes. A battle has waged for years along the U.S.-Mexico border over what fundamental human rights migrants crossing through the dangerous region are entitled to, if any at all, IBT reported Sunday.

The new provisions could serve to make crossing the border even less safe, as migrants are forced to pay local cartels for safety as they avoid U.S. immigration officials as they ramp up their efforts to round up undocumented immigrants.

"Virtually every immigrant is now a priority for detention and deportation.  Immigration and border agents will increase dramatically in number and are empowered to operate unfettered," the ACLU wrote. "State and local law enforcement agencies, including those with records of racial profiling and police brutality, are encouraged to become immigration agents."