MEXICO CITY – Retired U.S. Gen. Barry McCaffrey, drug czar under former President Bill Clinton, said Wednesday the war against drugs is a bigger problem than the war against terror.

Speaking at a news conference in Mexico City, McCaffrey said 52,000 people die from drugs each year compared to the 12,000 U.S. troops that have been killed or wounded in Iraq since the war started.

Better cooperation between Mexico and the United States has helped win small battles in the fight against drugs, McCaffrey said, adding that the countries now share evidence and have common laws for money laundering, polygraph testing and wire tapping.

"Ten years ago we had zero legal cooperation on extradition between the U.S. and Mexico. Now it's not true," he said. "The U.S. extradites American citizens to stand trial in Mexico, and Mexico has extradited some U.S. and bi-national citizens to stand trial in the States. A lot remains to be done, but we're getting better."

McCaffrey denied the idea that drug cartels in Mexico are merging to gain power, despite comments published Wednesday in Mexico from organized crime prosecutor Jose Luis Santiago Vasconcelos, who said two major drug cartels are now controlling Mexico's drug trade.

Santiago Vasconcelos said the two main cartels are headed by Osiel Cardenas Guillen, currently in jail, and Joaquin "El Chapo" Guzman, escaped from jail, and he added that both groups are warring for control of the country's drug routes.

He also said the Arellano Felix gang, once believed to be the country's most powerful, is now controlled by Cardenas.

But McCaffrey said he doubted the claims.

"It's impossible to believe a criminal organization will come together in trust," he said. "It's about money, destruction of children, work ethic and democracy. There's probably 30 organizations and a 100 more north of the border."

McCaffrey said he had confidence in federal Attorney General Rafael Macedo's ability to carry out the war against drugs, adding that Mexican soldiers had made improvements in fighting corruption that needed to be replicated by law enforcement.