Reuters video shot from Ciudad Juarez in Mexico showed military helicopters flying above and armed soldiers by a border fence.
Although the migrants are still in the country’s south and in Mexico City, President Donald Trump has reportedly sent over 5,000 soldiers to the border in response.
Trump has hardened his stance on immigration, and specifically against the caravan of migrants. This week, he effectively suspended the granting of asylum to migrants who cross the U.S.-Mexico border illegally, seeking fresh ways to block thousands of Central Americans traveling in caravans from entering the United States.
Trump has said the United States could send as many as 15,000 troops to the border, more than are in Afghanistan.