MATÍAS ROMERO, Mexico — With a sarcastic half-smile, Nikolle Contreras, 27, surveyed her fellow members of the Central American caravan, which President Trump has called dangerous and has used as a justification to send troops to the border.

More than 1,000 people, mostly women and children, waited patiently on Wednesday in the shade of trees and makeshift shelters in a rundown sports complex in this Mexican town, about 600 miles south of the border. They were tired, having slept and eaten poorly for more than a week. All were facing an uncertain future.

“Imagine that!” said Ms. Contreras, a Honduran factory worker hoping to apply for asylum in the United States. “So many problems he has to solve and he gets involved with this caravan!”

The migrants, most of them Hondurans, left the southern Mexican border city of Tapachula on March 25 and for days traveled north en masse — by foot, hitchhiking and on the tops of trains — as they fled violence and poverty in their homelands and sought a better life elsewhere.