Colombia's government and FARC guerrillas reached agreement Wednesday on the rebels' future participation in politics, a deal that brings the country closer to ending a half-century of civil war.

The accord was a much-needed boost to year-long peace talks that had appeared to be close to stalling in recent months, with President Juan Manuel Santos repeatedly warning the process was dragging on without progress.

The rebels' political reintegration was one of five agenda points under negotiation between Santos's government and the Revolutionary Armed Forces of Colombia (FARC).

"We have reached fundamental agreement on the second point of the agenda," they said in a joint statement read out in Havana by a Cuban diplomat, Rodolfo Benitez, confirming the political deal.

Humberto de la Calle, a former vice president who is the Colombian government's lead negotiator, said: "This new democratic opening will clear the way for peace to definitely take root, once the conflict ends."

The FARC's top negotiator, Ivan Marquez, also expressed optimism.

"The important aspects that we have agreed on so far in terms of political participation give Colombians the possibility of beginning to open the doors to a true democracy," Marquez said.

"Still, there is a long way to go," he added.

Santos stressed that negotiators would not be stopped from getting the job done due to time concerns.

"It would be really irresponsible to break off talks, or to have a pause in them, when we are making real progress," Santos said. "It would be really irresponsible to blow the greatest shot the country has had at peace over political or time concerns."

The sides must reach agreement on three more issues -- drug trafficking, compensation for victims, and disarmament -- to finalize a comprehensive accord ending Latin America's longest-running insurgency.

Marquez stressed the need to "respect the right to life, to differences, to a political option, and not stigmatization."

He was referring to a period in the 1980s when members of the FARC demobilized to form the Patriotic Union movement, 3,000 of whose members and leaders were subsequently assassinated.

In May, the government and the FARC reached agreement on how to approach land reform and rural development, the first agenda item and the root of the conflict.

Norwegian diplomat Dag Mylander, also reading from the joint statement, said the agreement "includes guarantees for the political opposition, measures to promote citizen participation and it contemplates revising the Colombian electoral system after a final peace agreement is signed."

Norway and Cuba are guarantors of the peace talks, which got fully under way in Havana in November 2012.

Negotiators went into overtime to clinch the agreement on how to reintegrate demobilized rebels, extending talks that were supposed to have ended last Thursday until it was hammered out.

Santos, who is running for re-election in 2014, had urged the FARC to speed up the process.

Shortly before the agreement was announced in Havana, Santos said the day was nearing that Colombia would be "a normal country -- a country at peace."

Santos, however, faces a challenge from the right from his predecessor Alvaro Uribe, who vehemently opposes the peace process.

Uribe has thrown his weight behind Oscar Ivan Zuluaga, who this week began collecting signatures for a presidential run against Santos.

Negotiators will now take a 10-day break before tackling the next agenda item: drug trafficking, which the FARC is alleged to have abetted to finance their operations.

The peace talks are Colombia's fourth attempt to find a negotiated settlement to the conflict.

A lasting peace accord?

Political experts who have been observing the progress of the negotiations, were optimistic that the country might finally be on the road to an enduring end to the conflict.

"The peace process cannot be rolled back," said Eduardo Celis, a researcher at Colombia's Center for Peace and Reconciliation, noting that a resolution now has been reached on the two major stumbling blocks, and that a comprehensive deal is all but certain.

"The two roots of the conflict are rural development and political participation -- everything else is flexible," he said.