During a one-day trip south of the border, Secretary of State Hillary Rodham Clinton on Monday lauded Mexico for battling drug cartels she once compared to an insurgency.

Clinton said President Felipe Calderon has been "courageous" in shouldering his share of the two nations' battle against cross-border criminal networks.

"This is very hard, and what President Calderon has done is absolutely necessary," Clinton said after meeting with Foreign Minister Patricia Espinosa in Guanajuato, a colonial-era mining city. "There is no alternative."

She vowed continued U.S. support through equipment and training for Mexican law enforcement, and by targeting the southbound flow of arms and money into Mexico.

Clinton later traveled to Mexico City to visit with Calderon, who declared war on drug cartels when he took power in December 2006.

Clinton's talks with Espinosa also touched on border management, trucking and climate change. The diplomats didn't announce any new initiatives in the war against Mexico's powerful traffickers. Last year, Clinton irked Mexican officials when she compared those groups to a Colombia-style "insurgency" of years past.

The central state of Guanajuato where Clinton and Espinosa met has been relatively free of the violence that has pushed the drug war high on the bilateral agenda. Nationwide, the death toll exceeds 34,000 in four years. Most of the killing stems from fighting among drug traffickers for control of smuggling routes and local markets.

The violence has sown terror in border cities such as Ciudad Juarez and the northern states of Tamaulipas and Nuevo Leon.

A day before Clinton's visit, seven men were killed in Ciudad Juarez — Mexico's most violent city — when unidentified gunmen opened fire with assault weapons at a public soccer field. Eight gunmen were reported killed in clashes Monday with Mexican troops outside the industrial city of Monterrey in Nuevo Leon.

The rising bloodshed pushed Calderon last year to seek U.S. help in bringing calm to Ciudad Juarez, according to a U.S. diplomatic cable made available by WikiLeaks and newly published by Spain's El Pais newspaper.