CARTAGENA, Colombia - Under a security web of warplanes, ships and 15,000 troops, President Bush praised Colombia's battle against drugs and Marxist guerrillas Monday and pledged to keep U.S. aid flowing so "this courageous nation can win its war against narcoterrorists."

In a country that is the world's largest producer of cocaine and a major supplier of heroin, Bush said President Alvaro Uribe is achieving results with a massive aerial fumigation program against coca - the main ingredient in cocaine - and an aggressive military buildup against insurgents, who fund themselves through drug trafficking, kidnapping and extortion.

"The number of acres under cultivation are down significantly," Bush said, standing with Uribe in shirt sleeves at seaside lecterns. "The number of arrests are up. The number of murders is down. In other words, this man's plan is working."

Uribe said Colombia is winning the fight, but has not yet won. "We have made progress but the serpent is still alive," Uribe said.

Bush's pledge reaffirms U.S. commitments to a $3.3 billion, five-year military aid program known as Plan Colombia. Bush said the plan launched in August 2000 enjoys widespread support in Congress and that he would work with lawmakers to keep it funded. Without mentioning a specific figure, Bush said he would seek enough funds to make the plan effective.

Bush left Cartagena for his Texas ranch to spend the Thanksgiving holiday, arriving in early evening. At Uribe's urging, he stopped off in this Caribbean seaport city after attending a summit in Chile of 21 Pacific Rim leaders. Security was tight.

U.S. Navy commandoes, toting assault rifles and peering through binoculars, patrolled the Caribbean in rubber boats where submarines and ships already plied the waters. Warplanes and helicopters provided air cover while 15,000 Colombian security forces were deployed around the city for Bush's brief stay.

Since Uribe came to power two years ago, Plan Colombia has helped jail scores of traffickers and reduce the coca crop by 20 percent for two years in a row, according to the White House.

And the battle against rebel groups is being expanded from the capital of Bogota to more rural areas. Still, the efforts have still failed to visibly reduce cocaine production or keep it off U.S. streets. And the 40-year-old insurgency continues to claim an estimated 3,500 lives every year.