The Department of Defense has reallocated over $600 million from the Afghan National Security Forces to build the wall, following Trump's national emergency declaration.
Tens of thousands of people belonging to U.S. Native tribes live in the Mexican states and routinely cross the border to participate in cultural events.
Protesters took to the streets at more than 140 events across the United States on Monday to oppose President Donald Trump's declaration of a national emergency on the country's southern border.
Within hours of Trump declaring a national emergency on the border, the ACLU announced it would sue the president to prevent him from using military funds to pay for border wall construction.
Recent polling reveals that most Americans oppose the expansion of the border wall, and two-thirds oppose Trump using emergency powers to fund its construction.