U.S. assistance to Mexico's battle against drug cartels "is not a handout" but rather an alliance against organized crime, Washington's envoy here said upon delivering a fourth Blackhawk helicopter as part of the Merida Initiative.

"With this helicopter, nearly $700 million in equipment and training have now been delivered to our partners in a multitude of government agencies, including the federal police, the attorney general's office and the military," U.S. Ambassador Anthony Wayne said in a ceremony at a police base in the Mexican capital.

After expressing his pride at the achievements of the Merida Initiative created in 2007 under the George W. Bush government, he noted that it has also helped train more than 50,000 Mexican government workers.

Mexican Public Safety Secretary Genaro Garcia Luna said that both nations face "with firmness and determination" the threats against their security.

"The guiding principle of the alliance between Mexico and the United States is a shared responsibility for the war on drugs," he said at a ceremony for the delivery of the Blackhawk UH-60M, worth some $20 million.

The aircraft, equipped with technology that permits nighttime operations, will strengthen the Mexican government's operations against organized crime.

The United States has provided Mexico with 15 helicopters as part of the Merida Initiative, including the three Blackhawks delivered to the Mexican navy in September.