The Department of Defense (DOD) is sending 1,140 additional U.S. troops to the southern border of the United States to help bolster the efforts of U.S. Customs and Border Protection (CBP) to control the influx of illegal immigrants.

“The DOD continues to work with the Department of Homeland Security to fill critical capabilities gaps at the southern border in accordance with President Trump’s Executive Order, ‘Protecting the American People Against Invasion,'” U.S. Northern Command (USNORTHCOM) said.

There are currently 4,300 U.S. active-duty troops at the southern border, and an additional 1,140 troops will bring the total to 5,440 active-duty service members.

USNORTHCOM said the additional troops will provide support to joint task force operations, including command and control of sustainable units and coordination of logistical support, field feeding support sites and control of logistical movement.

The Pentagon is seen from a flight taking off from Ronald Reagan Washington National Airport in Arlington, Va.  (Alex Wong/Getty Images)

Secretary of State Marco Rubio said at the time of the announcement this month there was a “sufficient factual basis” under section 219 of the Immigration and Nationality Act to issue the designations against the gangs and cartels.

The Trump administration also began sending flights of illegal immigrants to the Guantánamo Bay detention site in Cuba earlier this month. 

Around 30,000 “criminal illegal aliens” could be held at the base that once housed hundreds of prisoners, only 15 of whom were left before Trump began sending migrants there.

Fox News Digital’s Rachel Wolf contributed to this report.