* Minister Pinzon sworn in, vows to improve security
* Says will carry out strategy revision
By Monica Garcia
BOGOTA, Sept 5 (Reuters) - Colombia's new defense minister vowed on Monday a forceful response to illegal armed groups and more innovation in confronting guerrillas and drug barons in the Andean nation.
Latin America's No. 4 oil producer has faced increasing criticism from what is popularly seen as deteriorating security in a nation where leftist rebels continue to battle government forces and gangs look to expand their crime networks.
"We're right in a moment of confrontation, in which again it's necessary to innovate and respond effectively to the changes and challenges that we face," Defense Minister Juan Carlos Pinzon said at his swearing in ceremony as minister.
"The order we received from the president, is to generate results, act decisively."
Pinzon, an economist and former deputy defense minister, took over as minister on Monday after the ex-chief quit in the face of growing criticism and the perception that security gains were being reversed. [ID:nN1E77U0T8]
Colombia's security has improved dramatically over the last decade as U.S. aid flowed in to help in the battle to curb drug production in the cocaine-fueled conflict, but guerrillas and gangs continue to challenge state control in some areas.
President Juan Manuel Santos came to power last year vowing to continue the hard-line stance against illegal groups pioneered by ex-President Alvaro Uribe, but Santos' popularity has taken a hit over perceptions that security is worsening.
The conservative leader and U.S. ally has said the country would develop better strategies to battle Marxist rebels who still manage attacks despite having been weakened. [ID:nN1E7760BJ]
The South American country has attracted billions of dollars in foreign direct investment over the last decade, boosting oil and coal output to historic highs after dealing blows to leftist guerrillas and cocaine cartels.
Pinzon -- who has worked for Citibank, the finance ministry and as an economics professor at local universities -- said he planned to look at investing more in technology and strengthening security for Colombians.
"Drug trafficking is the biggest drag on, the worst pain that has plagued Colombia," Pinzon said at a miliary ceremony. "It remains the fuel of all crimes in the country and we must continue (fighting)," he said. (Writing by Jack Kimball; Editing by Todd Eastham)