Colombia's government has formally launched peace talks with leftist FARC rebels. The closed-door talks in Norway are the latest attempt to end almost five decades of conflict.
The Colombian government and the Revolutionary Armed Forces of Colombia (FARC) held their first direct talks in 10 years on Thursday in a hotel in Hurdal, a small town north of Norway's capital, Oslo.
"We've come to look for peace with social justice in Colombia," Marquez said. "We come with an olive branch in our hands."
De la Calle meanwhile expressed "moderate optimism" about reaching a peace deal after three earlier failed attempts.
"We hope that there will be good results for the Colombian people," he said. "This is a moment of hope."
The talks are to continue with in-depth negotiations in Cuba's capital, Havana, starting on November 15. They will follow preparatory meetings on November 5.
They are expected to cover the laying down of arms, rural development, land distribution, narcotics trafficking, victims' rights and various guarantees for the opposition.
The guerrillas formed in 1964 to demand what they viewed as a just distribution of land. Initially, a number of Colombians supported the guerrilla fighters' demands. However, as the war has dragged on, the death toll in connection with the conflict has risen to about 600,000 and there is growing support for an end to the fighting.
ccp/mkg (AFP, dpa, Reuters)