BOGOTA -- The nation’s largest guerrilla group and government officials formally launched peace talks Thursday in an event that underscored deep divides even as it held the promise of bringing an end to the hemisphere’s longest civil conflict.

After months of secret talks and growing expectations in this war-weary nation, the chief negotiators for the Revolutionary Armed Forces of Colombia, or FARC, and the government said they would begin tackling the five-point peace agenda on Nov. 15 in Cuba.

At a joint press conference in Oslo, Norway, the two factions said the first point of discussion would be land reform and agricultural development. Colombian farmers have been at the heart of the nation’s 48-year-old conflict and almost 6 million people have been forced off their land due to violence.

But Thursday’s carefully orchestrated event also highlighted potential problems.

In a feisty opening statement, the FARC’s chief negotiator Iván Márquez hinted that the group might not stick to the agenda, saying everything from the nation’s economic model, free trade deals, and military war crimes need to be addressed.

“We want peace,” Márquez said. “But peace doesn’t mean the silencing of guns — it means transforming the structures of the state and changing our political, economic and military models.”

Colombia’s chief negotiator, former Vice President Humberto de la Calle, shot back later at a news conference, suggesting the rebels were trying to rewrite the rules.

“We are not negotiating our economic model and we are not negotiating foreign investment,” he said. “For those things to be part of the Colombian agenda, the FARC needs to lay down its arms, participate in politics and win elections.”

The first public encounter between the two sides suggested the process won’t be as fast, secret or smooth as the government hoped, said Ariel Ávila, a conflict researcher at the Corporación Nuevo Arco Iris, a Colombian think-tank.

“They both put their cards on the table and it’s clear that this won’t be easy,” he said. “There’s 50 years of history here.”

But the fact that both sides were even in the same room was something of a coup for President Juan Manuel Santos, who’s staking his political future on the talks.

In August, the government announced that secret meetings in Cuba had laid the groundwork for negotiations. The peace plan revolves around five points: agricultural reform, the guerrilla’s rights to political participation, the FARC’s withdrawal from the drug trade, the recognition of victims rights, and ending the conflict.

Santos has said the talks will be measured in “months not years” and warned that he’ll pull out if there is any stalling.

Many here recall the 1999-2002 peace process that led the government to demilitarize an area the size of Switzerland. When those talks failed, many blamed the concession for allowing the FARC to regroup and wreak havoc over the next decade.

On Thursday, de la Calle warned that the military will keep up its attacks even as talks progress. Only when the final agreement is signed will a ceasefire be implemented, he said. The FARC had been pushing for an immediate end to hostilities and brought it up again at the news conference.