"It's indispensable that the fight against organised crime is fully assumed as a shared responsibility between the United States and Mexico ... with each on its territory and in its field of competence," Mr Calderon said on a visit to the city, which is considered the world’s most dangerous.
Mr Calderon's third visit this year to Mexico's crime capital followed the high-profile murders of an American employee of the US consulate who was three months pregnant, her husband and the husband of a Mexican consular employee in two separate weekend attacks.
A seven-month-old baby, found crying in the back of a bullet-riddled car, was among the few survivors of the two hit-and-run shootings that took place minutes apart in Ciudad Juárez at the weekend. She was being cared for by relatives on Monday while funeral arrangements were being made for her parents, who were found in the front of their car with multiple gunshot wounds to the head and neck.
The victims were identified as Lesley Enriquez, an American working at the consulate, her American husband Arthur Redelfs and Jorge Alberto Salcido, the Mexican husband of another consular employee.
American officials removed their families from a string of northern consulates and the FBI joined the hunt for the killers of the couple, who were the first US Government employees to die in the long-running battle between crime cartels. Mexican authorities have blamed the latest murders on "the Aztecas," hitmen linked to the powerful Juarez drug cartel.
Yesterday Mr Calderon was met with protests by hundreds of residents in Ciudad Juarez who are frustrated by the almost daily attacks, extortion and kidnappings that plague the city, despite the deployment of around 6,000 troops.
Some protestors threw stones at police ringed around the hotel where Mr Calderon was holding meetings and others managed to jump over barriers police had set up to limit access to the building. At least eight protestors were arrested.
Accompanied by the US Ambassador to Mexico Carlos Pascual, the Mexican leader stressed the key role of US drug consumption and weapons trafficking in funding the Mexican gangs.
President Barack Obama's administration has acknowledged the US role in Mexico's violence and American officials have targeted Mexican drug gangs in the United States in recent years.
Mr Pascual dismissed reports that US forces would carry out operations inside Mexico, saying they had been sent to assist their Mexican counterparts.
"No US law enforcement officers will conduct operations in Mexico," he said. "US agencies are in Mexico to support the Mexican authorities who have jurisdiction over the investigation."
Ciudad Juarez is at the heart of Mr Calderon's controversial clampdown on organised crime, which has seen some 50,000 troops deployed nationwide.
More than 15,000 people have died in the surge of drug-related violence since Mr Calderon took office at the end of 2006, including more than 2,600 last year alone in Ciudad Juarez.
Investigators said it remained unclear why the US consulate-linked victims were singled out by hit teams who ambushed the two family groups just minutes apart Saturday after they left a birthday party.
