If Trump really wanted to stop people fleeing Central America..
I have some suggestions:
From the State Department Travel Advisory for Honduras :
Violent crime, such as homicide and armed robbery, is common. Violent gang activity, such as extortion, violent street crime, rape, and narcotics and human trafficking, is widespread. Local police and emergency services lack sufficient resources to respond effectively to serious crime.
I have read somewhere that the police often don't even have money for gasoline.
1. Meet with the governments and create aid packages that aim to assisting them in fighting violent crime. The main reason people flee is because they fear for their lives. They fear for their lives and know that the police can't or won't do anything about it.
2. Help them encourage economic development which would provide jobs. Jobs would generate taxes which would help to pay for police and infrastructure. If people have good jobs and security they aren't as likely to want to come to the US.
Instead Trump wants to build a wall and threatens to end all foreign aid to these countries. He could put conditions on the aid, such as there has to be tangible results or that that the us send police (not military) advisors to help set up police academies and train police management. It seems to me it would cost less than a wall, an armed force on the border and mothers and children in concentration camps.