Ahead of his visit to Mexico, President Barack Obama on Wednesday imposed sanctions on three Mexican organizations he designated as cartels at the center of the country's violent drug war. White House spokesman Robert Gibbs said the groups—the Sinaloa Cartel, Los Zetas, and La Familia Michoacana—would be sanctioned under legislation called the Foreign Narcotics Kingpin Designation Act. Obama's move allows the Treasury Department to block or seize any assets under U.S. jurisdiction from the cartels or anyone acting on their behalf. “Today's action underscores the U.S. government's support for President [Felipe] Calderon's courageous attack on the cartels and our attempts to attack the financial underpinnings of Mexico's cartels, believed to generate billions of dollars annually,” Gibbs told reporters. Earlier, a Homeland Security official said the Obama administration would name a high-ranking official to deal with illegal immigration and drug-violence spilling over into the United States. Obama on Thursday will be the latest high-ranking U.S. official to visit Mexico to discuss drug-related violence, following recent trips by Secretary of State Hillary Clinton, Homeland Security Secretary Janet Napolitano, and Attorney General Eric Holder.