That will add to the estimated 2,000 National Guard troops there since April.
Previously, Trump had referred to some of the migrants making the trek to the border as "hardened criminals" and suggested that "unknown Middle Easterners" were among the crowds.
The U.S. official was not authorized to speak publicly because not all details of the military arrangement had been worked out, and so spoke on condition of anonymity.
What do people in California think about migrant caravan pushing north through Mexico with the goal of crossing the southern border into America?
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The back is a mix of magnesium and aluminum (only on the kickstand) but in a matching finish that keeps things looking uniform. The device is marketed as an "always on, always connected PC" just like any other Windows 10 device based on Qualcomm's chips.
The Department of Homeland Security requested the troops, NPR's Tom Bowman reports, after President Trump said he is intent on stopping any of the migrants from crossing the border.
Secretary of Homeland Security Kirstjen Nielsen told Fox News on Thursday night that "everything is on the table" in regard to the migrant caravan.
The additional troops are to provide what one official described as logistical support to the Border Patrol, including a variety of things such as vehicles, tents and equipment.
Central American migrants walking to the United States start their day departing Ciudad Hidalgo, Mexico, Oct. 21, 2018.
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Both the PS4 and Xbox One S versions of the game seem to use lower resolution textures than their 4K-targeted counterparts. PS4 Pro makes a valiant effort to stick around 30fps as well, but it slows down more easily when the going gets tough.
"This caravan can not come to the United States", Nielsen said. Many are fleeing violence, poverty and government corruption in their home countries. It was not immediately clear why active duty forces were chosen, since National Guard troops can perform the same functions. "Go back to your Country and if you want, apply for citizenship like millions of others are doing!"
The United Nations estimates that 7,000 people have joined the caravan since it set out from San Pedro Sula, Honduras, on October 13. "They will not be allowed to stay".
Despite the Trump administration's claims that the migrants are trying to enter "illegally", current USA law allows foreign nationals to apply for asylum at a port of entry at the border.
The official said the troops would satisfy elements of a "wish list" for military assistance sent to the Pentagon by the Department of Homeland Security, the USA agency with responsibility for the border. You're going to see a very secure border.
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On that day, Julio Baptista scored the only goal of the game to collect all three points for Bernd Schuster's side. Wednesday's match is an incredibly important one, with the two sides tied for first place in Group B.