Sprawling tents on the US border have been raised as Mexico braced for President Donald Trump to fulfill his pledge to carry out mass deportations.

By Laura Gottesdiener and Lizbeth Diaz CIUDAD JUAREZ, Mexico (Reuters) - Mexican authorities have begun constructing giant tent shelters in the city of Ciudad Juarez to prepare for a possible influx of Mexicans deported under U.

The Pentagon is deploying up to 1,500 active duty troops to help secure the southern border in the coming days. The Department of Defense will also provide military aircraft to assist with deporting detained migrants from San Diego and El Paso.

Eighteen states and the ACLU filed lawsuits seeking to prevent President Trump from denying citizenship to children born in the U.S. to non-citizens.

ALCU Deputy Director Lee Gelernt and Immigration Attorney Michelle Canero speak to NBC News' Tom Llamas about President Trump's executive order on challenging birthright citizenship and what this could mean for Americans.

This story was updated on Jan. 21 at 6:08 p.m. to reflect that the ACLU’s lawsuit was filed on Monday, not Tuesday. Hours after President Donald Trump issued an executive order Monday barring birthright citizenship to children of undocumented residents,