A steep decrease in undocumented immigrants entering the U.S. has been seen recently by Border Patrol due to Mexico's increased efforts to arrest Central Americans trying to pass through.

NPR reported that since the U.S. put pressure on Mexico to help decrease the number of immigrants, critics say the U.S. got Mexico to do its dirty work.

Mexico has amped up the number of immigration checkpoints, as well as authorities preventing travel on the freight trains, popularly called La Bestia (The Beast), making it harder for the Central American migrants to make it through.

These efforts have resulted in an almost 60 percent decrease in migrants at the border.

More than 30,000 Central Americans have been sent home, many of whom are children, Mexico's Interior Minister told NPR.

But by comparison, the southern border of Mexico is wide open, allowing easy access from Guatemala, NPR reported.

The immigrants spoke to NPR and detailed their personal troubles, and what has spurred their persistence in pursuing a chance to enter the U.S.

While risking their lives to better their families', and fleeing violent threats at home, many of the travelers are walking through the woods in the dark to avoid being seen.

The reduction in immigrants is only perceivable in the U.S. because of Mexico's efforts, but in reality the number of Central American migrants hasn't waned.

"We are now the servants of the U.S. in this role," Sergio Aguayo, a professor at El Colegio de Mexico, told NPR. "It is not a simple issue that can be solved by closing the doors of Mexico or convincing them not to come."

Aguayo added that the problems that are forcing the migrants to attempt entry to the U.S. have not disappeared, so the number of migrants won't decrease. Faced with poverty, exploitation and violence, the families still hold on to the American Dream.