Colombia's president has vowed to destroy every coca plant in the region where 29 soldiers died in one of the worst rebel attacks in recent years.
The attack was a setback, President Uribe admitted
The troops had been protecting workers who were destroying crops of coca, the leaf used in the production of cocaine.
Outnumbered by about five-to-one by Farc rebels, the soldiers died in a hail of artillery fire and explosives.
Correspondents say the left-wing Farc may be stepping up attacks as President Alvaro Uribe seeks re-election in 2006.
President Uribe acknowledged that the attack - one of deadliest since he took office in 2002 - was a setback.
"It pains us immensely, but we are not discouraged," he told reporters during a visit to the scene of the ambush near Vista Hermosa, some 170km (105 miles) south of the capital, Bogota.
Mr Uribe - who has taken a hardline against the rebels - vowed to hunt down those involved in the attack.
Most coca eradication in Colombia is done by spraying chemicals from planes.
But the crops in Vista Hermosa were being eradicated by hand because of their close proximity to the Sierra Macarena National Park, which could be harmed by fumigation.
The soldiers were outnumbered five-to-one
Mr Uribe said that this was why the Farc had begun growing much of its coca inside the country's national parks.
"The world needs to know the following: natural parks such as the Macarena have been violated by narco-terrorism," he said.
"More than 60 eradication groups will concentrate on Macarena National Park. They will not leave until they have manually eradicated every last coca plant."
The illegal drugs trade is a key source of funding for armed groups, who are estimated to make hundreds of millions of dollars a year from it.
The Farc and the smaller National Liberation Army (ELN) have been involved in a 40-year conflict with state forces and right-wing paramilitary groups.
Tens of thousands of civilians are known to have been killed in the conflict.
Mr Uribe is engaged in peace talks with right-wing paramilitaries and is in preliminary negotiations with the ELN.
The Farc has so far refused to hold talks with Mr Uribe's government, although both sides have said they are willing to exchange hostages for jailed rebels.