Colombia President Juan Manuel Santos hopes for peace

Colombia's President Juan Manuel Santos has said he hopes to sign a peace treaty with left-wing rebels this year, ending the 50-year-old conflict.

Mr Santos told the BBC the Farc rebels had been weakened and that security had improved in Colombia.

But he defended his opposition to a ceasefire, saying both military pressure and peace talks were needed to end the war soon.

The two sides have been in negotiations in Cuba since November 2012.

He said he hoped they were close to peace.

"I am today more optimistic than I was a year ago," he told the BBC at the World Economic Forum in Davos, Switzerland.

"They (the rebels) still have the opportunity and the capability of committing terrorist acts (....) but the strength that they had before of taking over small towns or controlling regions, that is no longer present."

'Carrot and stick'

Rebel attacks have continued. On Friday authorities said two police officers had been killed in southern Colombia.

But Mr Santos reiterated a vow to keep military pressure on the Farc even as his government pursued a comprehensive peace in Cuba.

"It's counterproductive but it's less costly than prolonging the conflict many years more.

And I think the best way to end it is by applying military pressure, in other words the carrot and the stick at the same time."

The talks in the Cuban capital, Havana, are the fourth attempt since the 1980s to reach peace, having failed before amid disagreements, mutual recriminations and flare-ups of violence.

But after more than 14 months, the two sides have only agreed tentatively on two points of a six-point agenda: land reform and political participation of the rebels in a post-war Colombia.

The conflict - the longest-running in Latin America - has killed an estimated 220,000 people since it began in the 1960s, with some three million more internally displaced by the fighting.