The Colombian government lashed out at leftist FARC guerrillas Tuesday for failing to actively work to dismantle minefields present in half the country's municipalities.

The government's chief negotiator, Humberto de la Calle, stressed that demining is "crucial for many Colombian communities."

"This is a subject we've been working on for months, and we want the public to be clear about the ... the need to move forward on these gestures," de la Calle said, breaking his usual silence during peace talks in Havana, which resumed Monday after a month and a half break.

Moments earlier, guerrilla leader Pastor Alape had declined to comment publicly about the minefields, which government negotiators say are in 668 of Colombia's 1,100 municipalities.

"We hope to deal with this issue at the negotiating table and not debate it here," he told reporters.

"There are issues on the table, and we are headed in the right direction," he added, declining to elaborate.

Since 1990, landmines have wounded or killed 11,006 people, according to retired general Oscar Naranjo, a government negotiator.

"The FARC have expressed their willingness to help with clearance," Naranjo told El Tiempo newspaper last month.

The Bogota government and the Revolutionary Armed Forces of Colombia have been negotiating for more than two years in Havana to bring an end to the 50-year insurgency, but key issues remain unresolved, including disarmament and how any agreement should be ratified.

Peace negotiations began in November 2012 and so far the two sides have agreed on three of the six points of the agenda to end the conflict, which is estimated to have claimed the lives of more than 220,000 people.

The two parties are currently discussing the sensitive issue of reparations for victims of the conflict.