May 10 (UPI) -- Defense Secretary James Mattis could respond as early as Thursday to a request by the Trump administration to send hundreds more troops to the southern border.
The Homeland Security Department is requesting 700 additional National Guardsmen, helicopters and other equipment for assistance with Customs and Border Protection missions, like Air and Marine units.
About 1,600 National Guard troops have already been sent to the U.S.-Mexico border. Mattis authorized up to 4,000 total troops to participate in border security efforts by the end of September.
The presence of National Guard troops has helped free up more agents to physically guard the border.
Troops are also providing support from the air, surveillance back-up and assistance with infrastructure projects like vegetation clearing and road maintenance.
In three and-a-half weeks on the job, the National Guard troops at the border have so far flagged 1,600 people crossing into the United States unlawfully. They have also confiscated about 1,000 pounds of marijuana, officials said.
The troops, though, are not making any arrests.
"Right now we are not having any contact with migrants," Mattis said earlier this week.