The United Sates is dropping off criminals at the Mexican border instead of prosecuting, Mexican President Felipe Calderon says.

At an immigration conference Thursday, Calderon accused the United States of deporting violent offenders to cities like Ciudad Juarez and Tijuana, instead of prosecuting in the States because it is cheaper.

The number of deportations in 2011 is almost double the amount of deportees with convictions in 2008. On Tuesday, U.S. Immigration and Customs Enforcement said the agency deported about 400,000 people during the fiscal year ending in September. That is the largest number of removals in the agency’s history.

“There are many who really are criminals, who have committed some crime and it is simply cheaper to leave them on the Mexican side of the border than to prosecute them, as they should do, to see whether they are guilty or not,” Calderon said. “And obviously, they quickly link up with criminal networks on the border.”

The U.S. embassy declined an Associated Press request for comment.

Undocumented offenders are deported to Mexico after completing their prison sentence in the United States.

Officials in Tijuana told the AP some of the deportees end up committing petty crimes. Mexican officials say they don’t have a way to run criminal background checks on deportees to see if they have pending charges in other areas of the country.