The troop mobilization indicates that President Trump is breaking with recent presidents’ practice of limiting deployments along the U.S.-Mexico border mostly to small numbers of active-duty soldiers and reservists.

Roughly 3,000 more active-duty troops will deploy to the southern border, the Pentagon announced Saturday, expanding a major military operation to curb illegal immigration — a central priority of the Trump administration.

The Pentagon is sending about 3,000 more active-duty troops to the U.S.-Mexico border as President Donald Trump seeks to clamp down on illegal immigration and fulfill a central promise of his campaign