President Donald Trump acknowledges Defense Secretary Jim Mattis during a reception commemorating the 35th anniversary of the attack on Beirut Barracks in the East Room at the White House in Washington, Thursday, Oct. 25, 2018. less
President Donald Trump acknowledges Defense Secretary Jim Mattis during a reception commemorating the 35th anniversary of the attack on Beirut Barracks in the East Room at the White House in Washington, ... more
Photo: Manuel Balce Ceneta, AP
President Donald Trump with Defense Secretary Jim Mattis speaks at a reception commemorating the 35th anniversary of the attack on Beirut Barracks in the East Room at the White House in Washington, Thursday, Oct. 25, 2018. less
President Donald Trump with Defense Secretary Jim Mattis speaks at a reception commemorating the 35th anniversary of the attack on Beirut Barracks in the East Room at the White House in Washington, Thursday, ... more
Photo: Manuel Balce Ceneta, AP
In this Oct. 23, 2018 image, a woman holds the book of numbers and names as she calls those that will be allowed to cross the border and request asylum in the United States, in Tijuana, Mexico. The first obstacle that migrants in a giant caravan may face if they reach the US border is a long wait in Mexico. To enter through San Diego, the wait in Mexico is a month or longer, spawning an unusual numbering system. less
In this Oct. 23, 2018 image, a woman holds the book of numbers and names as she calls those that will be allowed to cross the border and request asylum in the United States, in Tijuana, Mexico. The first ... more
Photo: Gregory Bull, AP
Central American migrants traveling with a caravan to the U.S. make their way to Pijijiapan, Mexico, Thursday, Oct. 25, 2018. The sprawling caravan of migrants hoping to make their way to the United States set off again, forming a column more than a mile long as the group trekked out of the town of Mapastepec in southern Mexico before dawn. less
Central American migrants traveling with a caravan to the U.S. make their way to Pijijiapan, Mexico, Thursday, Oct. 25, 2018. The sprawling caravan of migrants hoping to make their way to the United States set ... more
Photo: Rodrigo Abd, AP
In this Oct. 23, 2018 image, people seeking asylum in the United States wait to receive a number at the border in Tijuana, Mexico. The first obstacle that migrants in a giant caravan may face if they reach the US border is a long wait in Mexico. To enter through San Diego, the wait in Mexico is a month or longer. less
In this Oct. 23, 2018 image, people seeking asylum in the United States wait to receive a number at the border in Tijuana, Mexico. The first obstacle that migrants in a giant caravan may face if they reach the ... more
Photo: Gregory Bull, AP
President Donald Trump listens to Defense Secretary Jim Mattis speak at a reception commemorating the 35th anniversary of the attack on Beirut Barracks in the East Room at the White House in Washington, Thursday, Oct. 25, 2018. less
President Donald Trump listens to Defense Secretary Jim Mattis speak at a reception commemorating the 35th anniversary of the attack on Beirut Barracks in the East Room at the White House in Washington, ... more
Photo: Manuel Balce Ceneta, AP
The Latest: Military working out border deployment details
WASHINGTON (AP) — The Latest on the Trump administrations plan to send troops to the U.S.-Mexico border (all times local):
10:42 a.m.
A U.S. official says Defense Secretary Jim Mattis has directed the military to work out details of a troop deployment to the southern border that could number 800 or more.
Mattis, who is traveling in the Middle East, signed paperwork accepting a written request for military assistance from the Department of Homeland Security. He also authorized the Pentagon's military staff to determine the size, composition and estimated cost of the deployment.
The intent is to have the troops in position to assist the Border Patrol by Oct. 31, the official said. The official spoke on condition of anonymity to describe aspects of planning that has not yet been completed or announced.
The troops are expected to provide a variety of air and land transportation assistance, as well as engineering help and other specialized forms of support like medical care.
12:19 a.m.
The Trump administration is planning to dispatch 800 or more active duty troops to the southern border at the direction of a president who has sought to transform fears about immigration into electoral gains in the midterms as a caravan of thousands of migrants makes its way through Mexico.
Defense Secretary Jim Mattis is expected to sign an order sending the troops to the border, bolstering National Guard forces already there. The action comes as President Donald Trump has spent recent days calling attention to the caravan of Central Americans slowly making their way by foot into southern Mexico, but still more than 1,000 miles (1609 kilometers) from U.S. soil.