Mexico deployed more troops to its southern border with Guatemala on Monday amid growing evidence that the heightened military presence was deterring some migrants from trying to cross the border.
Mexico's president Andrés Manuel López Obrador has pledged to send 6,000 troops to increase border security, but a senior government official says not all of these troops are going to the southern border.
Instead, some are being distributed across the northern border and other areas as well.
A deputy in Mexico's foreign ministry says since Saturday 426 soldiers have been deployed to the border town of Tapachula.
On the Suchiate river that forms part of Mexico's southern border with Guatemala, usually bustling cross-water commerce appeared to slow, a day after just six marines appeared on the Mexican shore.
Merchants and politicians expressed concern that the immigration crackdown could impact the commerce that communities on both sides depend on.
The mayor of Ciudad Hidalgo urged the troops to let local traders go about their business.