President Donald Trump is set to expand military presence at the U.S.-Mexico border by about 5,000 troops, according to reports.

Previously, it was revealed that Trump was sending about 800 troops to deal with the impending arrival of the migrant caravan making its way up through Mexico and toward the U.S. border.

What's happening now?

According to a Monday USA Today report, the Pentagon is set to deploy 5,000 active duty U.S. troops to the border in an attempt to prevent the migrants from entering the country.

The order is being carried out as a migrant caravan of more than 7,000 people slowly treks from areas in Central America to the U.S.-Mexico border.

The report noted that there are already about 2,100 National Guardsmen stationed along the border from a presidential order enacted earlier this year. This will bring the total up to more than 7,000 troops.

A Department of Homeland Security official who spoke on the condition of anonymity told the outlet that a formal announcement is forthcoming. The official noted that Trump is expected to deliver a speech Tuesday detailing actions his administration plans to take in order to stop the forward movement of the caravan, which Trump, on Monday, said has "many gang members" and "some very bad people."

In a Monday tweet, Trump wrote, "Many Gang Members and some very bad people are mixed into the Caravan heading to our Southern Border. Please go back, you will not be admitted into the United States unless you go through the legal process. This is an invasion of our Country and our Military is waiting for you!"

Many Gang Members and some very bad people are mixed into the Caravan heading to our Southern Border. Please go back, you will not be admitted into the United States unless you go through the legal process. This is an invasion of our Country and our Military is waiting for you!

— Donald J. Trump (@realDonaldTrump) October 29, 2018

Anything else?

A previous report noted that troops deployed to the border were not there for policing purposes, but to offer support to Border Patrol agents and would likely help to provide reinforcement materials, such as “fencing, wall materials, and other technical support at key points along the border where it is believed the migrants may try to cross.”

The troops are also to supply “tents and medical care for border authorities in those areas.”

On Sunday, U.S. Defense Secretary Jim Mattis said that troops have already begun the process of transporting jersey barriers to fortify the U.S.-Mexico border.

According to the Washington Times, Mattis said that details of the new deployment — including a troop count — are still being worked out.

Typically, National Guardsmen perform the duties that the active duty troops are reportedly set to perform — so it remains unclear as to why active duty troops are purportedly being sent to the border as opposed to more National Guardsmen.