Defense Secretary Pete Hegseth vowed during a visit to the southwestern border on Monday to use thousands of U.S. active-duty troops to help stem migrant crossings, a top priority for President Trump.

U.S. Defense Secretary Pete Hegseth's first trip since taking office will be to the United States' border with Mexico on Monday, in the latest sign that fortifying the border will be a priority for the Pentagon under President Donald Trump.

Although active-duty troops have been sent to the border by administrations of both parties, including the Biden administration, visits by Defense secretaries are uncommon. In 2018, Defense Secretary Jim Mattis visited troops at the border as the Trump administration considered another troop buildup there.