Migrants jumped border fences from the Mexican cities of Tijuana and Ciudad Juarez, to turn themselves in to U.S. border patrol officials, hopeful that the move may hasten their applications for asylum.
The U.S. government says it is struggling to deal with a surge of asylum seekers from countries in Central America who travel through Mexico.
On Saturday, the US cut aid to El Salvador, Guatemala, and Honduras in response – a move Democrats warned would only worsen the situation.
Under former President Barack Obama a system dubbed “metering” began, which limits how many can ask for asylum each day in Tijuana. Lawyers say President Trump is using the system more aggressively to stem the flow at the port of entry.
Shutting the southern frontier completely would disrupt billions of dollars in trade and millions of legal border crossings.