Concern is growing in the US about how to stop drugs being smuggled into the country from Mexico. There are also fears that the rampant violence between Mexican drugs cartels could spread across the border.
The boundary, some 2,000 miles (3,200km) long, between Mexico and the US is reported to be the busiest international border.
Every day, hundreds of thousands cross legally but every day also sees money and weapons smuggled south, and drugs brought across to the north.
In the Texan city of El Paso and the Mexican city of Juarez, monitoring the border has become a huge problem. The two communities live right up against one another, at the heart of a drugs smuggling route that is worth billions.
If you head out with the US Border Patrol here you get a good idea of how hard it is to stop traffickers getting across.
Agent Joe Romero and his colleagues have a huge desert region to patrol.
Fences have been built in some places, but Agent Romero agrees that surveillance and fences alone cannot stop the drugs trade.
“It’s a huge business. It’s a major part of an economy. Whether it’s a legal economy or an illegal economy it’s a big part of that. And there’s a big demand for it. That side is supply, and there’s a big demand for it on the US side.”
