Jim Mattis
Mattis reportedly told an aide, "We’re not going to do any of that."
The department's creation will require approval and funding from Congress.
Thousands of children have been separated from their parents in recent weeks as part of the Trump administration's zero tolerance policy.
The new national security adviser names as his deputy a foe of Defense Secretary Jim Mattis.
WHAT'S HAPPENING
President Trump says he’s considering a retaliatory attack on Syria, after dictator Bashar al-Assad used chemical weapons on his own people.
The Department of Defense authorized funding for up to 4,000 National Guard troops to secure the border.
Also on Friday, Defense Secretary Jim Mattis authorized the deployment of 4,000 National Guard troops to the border.
Troops may be heading to the border as early as Wednesday night, Homeland Security Secretary Kirstjen Nielsen said.
The president said he discussed the idea with Defense Secretary Jim Mattis.
But it's still unclear what Defense Secretary James Mattis actually recommended.