President Donald Trump has ordered Homeland Security Secretary Kirstjen Nielsen to prevent "large caravans" of people from entering the U.S. at the U.S.-Mexico border, he wrote in a Monday tweet.
The president appears to be referencing a group of migrants that are traveling from Central America through Mexico to the U.S.
In a follow-up, the president called on Mexico to put a stop to people traveling through Mexico to the U.S., while praising that country’s border laws as "very tough."
"We may make this a condition of the new NAFTA agreement," Trump wrote in the follow-up tweet. "Our country can not accept what is happening."
Trump has used the caravan to put a spotlight on U.S.-Mexico border issues. Early in April, Mexican officials ramped up efforts to register a diminishing group of hundreds of largely Central American migrants, seeking to disperse the "caravan."