The Mexican leader attended the memorial service of Edgar Millan Gomez and two other federal officers killed this week as cartels unleash a wave of violence across Mexico.
A defiant Calderon vowed to redouble his government's efforts in going after gangs.
"Organized crime is reacting this way because they know and feel we are hitting their criminal structure and operations," Calderon said during a visit to the border city of Reynosa, across from Texas, hours after the funeral service in the capital. "They know that Mexicans will no longer live in submission, and we are determined to take back our streets."
Calderon praised Millan Gomez for putting up a fight even after being shot several times outside his home on Thursday.
"Before he died, he still had the courage to capture his killer with his bare hands," Calderon said.
The two other officers were killed Wednesday in a shootout with suspected drug traffickers in southern Morelos state.
Since taking office in 2006, Calderon has sent more than 25,000 troops to drug hotspots. Cartels have responded with unprecedented violence, beheading police and killing soldiers. Drug-related violence killed more than 2,500 people last year alone in Mexico.
In the past week, federal police have suffered an onslaught of attacks. Millan Gomez was the third high-ranking federal official killed in Mexico City since May 1.
He was responsible for coordinating operations between federal police and the army - many of them targeting drug trafficking. He was named acting chief March 1 after his superior was promoted to a deputy Cabinet position.
On May 1, he announced the arrest of 12 suspected hit men tied to the Sinaloa cartel.
Hours later, a federal intelligence analyst was killed in Mexico City by assailants who tried to steal his car, and a federal commander was gunned down the next day.
Police would not comment on whether the Sinaloa cartel was behind Millan Gomez's killing, but said they were investigating possible drug links. Police have been interrogating one of the alleged gunmen.
Meanwhile, Mexico City authorities announced the arrest of a fifth suspect linked to a failed plot to bomb a Mexico City police commander. The homemade bomb exploded two blocks from police headquarters on Feb. 15, killing a man who carried it in a duffel bag and injuring a woman whom surveillance video captured walking with him.
Three men and a woman had already been arrested in the plot, which was traced to the cartel's home state of Sinaloa. Five additional suspects are still being sought.
In Washington, Thomas Shannon, the U.S. assistant secretary for Western Hemisphere affairs, urged Congress to approve the Merida Initiative, a US$1.4 billion (euro910 million) proposal to help fight drug crime in Mexico and Central America. President Bush wants Congress to approve US$550 million (euro355 million) of the package, the majority of which would go to Mexico.
"Central America and Mexico are facing public security threats of tremendous proportions," Shannon told the House Subcommittee on the Western Hemisphere. "The leaders of the region have shown that they are committed to working together to stop the growing violence and crime, but their resources are limited."
