While the caravans are mostly composed of family members and unaccompanied minors, criminals and drug traffickers, Donald Trump fears, could mingle in the crowd. "And sometimes enabling missions - especially if that's all you're going to do - require a significant footprint", he said, pointing out that U.S. troops deployed to the border will serve as "enablers" rather than "trigger-pullers". Command officials anticipate sending almost 5,200 active duty soldiers, sailors, Airmen and Marines to US border states, to serve as logistics and support units to the already 2,000 National Guard units already stationed there.
Tackling migrant solidarity protests and counter-protests, if they turn violent, will become yet another challenge for the soldiers.
He also said the administration will require all asylum seekers make claims at official ports of entry. -Mexican border could reach 15,000 - roughly double the number the Pentagon said it now plans for a mission whose dimensions are shifting daily.
President Donald Trump said he's ready to deploy as many as 15,000 troops to the southern border of the USA, triple the amount his administration announced a day ago, in a bid to stop or detain a caravan of migrants traveling north to the U.S.
Trump has ramped up his tough stance on illegal immigration, an issue that appeals to his core supporters, before elections on Tuesday that will determine whether his fellow Republicans keep control of Congress. "The United States can not possibly absorb them all", Trump said during a news conference at the White House.
That means more than 9,000 troops have already been committed to military operations on the border and Trump, who is prone to hyperbole, on Wednesday said the final number could swell to 15,000 troops.
A second, smaller group of 1,000 or so migrants is more than 200 miles behind the first caravan.
Trump claimed members of the caravans "Fought back hard and viciously against Mexico at Northern Border before breaking through".
"Immigration is a very, very big and very unsafe - a really risky topic and we're not gonna allow people to come into our country that don't have the well being of our country in mind", he added before insisting that he is not "fear mongering".
Associated Press President Donald Trump launched his campaign with an attack on immigrants and hasn't stopped since.
Watch: As Trump Preps to Send Troops on the Border, Here's Why.
Echoing their countrymen in the initial caravan, Hondurans in the second group talked of fleeing poverty and gang violence in one of the world's deadliest countries by homicide rates.
"These are tough people", Trump said about caravan members attacking Mexican soldiers and forcefully breaking through worldwide borders.
President Trump is delivering last-minute remarks on immigration from the White House's Roosevelt Room, CBS News has confirmed through a White House official.
It was reminiscent of the infamous "Willie Horton" ad used against Democratic presidential candidate Michael Dukakis in 1988 and condemned as racist.