BOGOTA, Colombia — In a Cuban government house in a leafy Havana neighborhood earlier this year, Colombian rebel commanders and their government adversaries secretly debated how to carve out a path to peace and end Latin America’s most intractable guerrilla war.

Colombia has been embroiled in violence since 1964, and as recently as 10 days ago there were few public signs that the two sides were considering a peaceful end to a conflict marked by hit-and-run strikes and terrorist bombings. But on Tuesday, President Juan Manuel Santos revealed that the talks in Cuba, which began in February and lasted six months, had produced a streamlined, five-point framework agenda for official negotiations that will open in October in Oslo before moving back to Havana.

“It’s a difficult road, no doubt very difficult, but it is a road that we have to explore,” Santos said in a nationally televised speech, flanked as he spoke by top military and political leaders. “Any responsible leader knows that you cannot pass up a possibility like this one to end the conflict.”

According to the most optimistic assessment offered by senior government officials, a peace agreement would be reached by April. That would bring to a close a drug-fueled war that has bedeviled not only numerous Colombian leaders but also the United States, Bogota’s closest ally and benefactor, which has spent on average $700 million a year here in mostly military aid.

Beginning with President Bill Clinton’s administration, the United States has steadily involved itself in Colombia’s fight to stem the northward flow of cocaine as well as in its broad anti-guerrilla strategy.

If a peace agreement is signed, the Revolutionary Armed Forces of Colombia, or FARC, would demobilize its far-flung units, disarm nearly 9,000 fighters and give up its long-stated aim of toppling the government.

Santos’s administration would guarantee that a rebel army that began its fight as a tiny peasant force in the hamlet of Marquetalia 48 years ago could transform itself into a legal social or political movement, government officials say. According to analysts, that is the most vital point for FARC commanders — and the most challenging for the government, which along with the United States blacklists the FARC as a terrorist group and accuses many of its leaders of war crimes and drug trafficking.

With a few scant details about the talks leaking out over the weekend, the FARC has signaled its support, even issuing a rap video Monday in which young rebels sing “about going to Havana — this time to converse.” The video ends with the guerrillas marching off, carrying a suitcase, a playful note for a group that inspires fear in many Colombians.

On Tuesday, the FARC’s leader, Rodrigo Londoño, better known by his alias Timochenko, said in a video released in Cuba that the guerrillas want “a lasting peace, democratic and just.”

In Washington, President Obama welcomed Santos’s announcement and called on the FARC to “take this opportunity to end its decades of terrorism and narcotics trafficking,” according to a White House statement.