HAVANA — After nearly five decades of violent struggle and failed attempts at detente, there is plenty of mistrust and bad blood between Colombia's government and the country's largest leftist guerrilla army. So a rebel spokesman's optimism about next month's peace talks in Norway offered an unexpectedly positive note just a day after the two sides seemed to be butting heads before negotiations even began. Marco Leon Calarca of the Revolutionary Armed Forces of Colombia, or FARC, told The Associated Press in an exclusive interview Friday that Colombian President Juan Manuel Santos' rejection of a proposed cease-fire will not derail next month's peace talks. Nor, he said, will the seeming improbability of a guerrilla imprisoned in the United States being freed to take part in the talks, as the rebels want. “These obstacles are nothing compared with all that has accumulated from ... 50 years of violence, which we are trying to solve through dialogue," Calarca said. “In that sense, looking at things optimistically, we think there is no problem we can't solve." The rebels had announced Thursday that a cease-fire was tops on their negotiating agenda, but Santos quickly rejected the proposal. “There's not going to be any cease-fire," the president told reporters Thursday night. “We will not give anything until we get the final agreement, and I want to make that very clear." Santos added that Colombia's military and police had even been told to intensify offensive actions. — AP