DHS asks for monthlong extension on troops at nation's southern border | 01 Dec 2018 | The Department of Homeland Security (DHS) has asked the Pentagon to extend the deployment of roughly 6,000 active-duty troops at the southern border with Mexico over a month, to Jan. 31, 2019, Fox News has learned. It is not immediately clear if Defense Secretary James Mattis has approved the request. The previous deployment orders have a Dec. 15 expiration. If Mattis does approve the request, thousands of soldiers who had planned to be home for Christmas will continue their deployment away from home.