(CBS SF) — More than 5,000 active-duty troops are being deployed to the U.S.-Mexico border ahead of the impending arrival of a migrant caravan, according to the Department of Defense.

Last week, the administration indicated it would send up to 1,000 active-duty troops to the Mexico border but the commander of the U.S. Northern Command and North American Aerospace Defense Command told reporters Monday the number of troops would be much larger.

“By the end of this week will we deploy over 5,200 soldiers to the southwest border,” said Gen. Terrence O’Shaughnessy. “That is just the start of this operation, we’ll continue to adjust the numbers and inform you of those.”

On Friday, Defense Secretary James Mattis approved a request by the Department of Homeland Security to send more troops to the southwest border in anticipation of the convoy of Central American migrants seeking asylum in the U.S.

O’Shaughnessy said the soldiers deployed will be armed. “We have the authority, give to us by Sec. Mattis, the units that are normally assigned weapons, they are, in fact, deploying with weapons,” he said.

There are already about 2,100 National Guard troops deployed along the border under an order from President Donald Trump issued earlier this year.