BOGOTA, April 18, (RHC-XINHUA) -- Colombian President Juan Manuel Santos on Friday urged the Revolutionary Armed Forces of Colombia (FARC) guerrillas to "set a deadline" for the peace process that was initiated two years ago.

The president said the government is losing its patience. The remarks came after tensions between the government and the FARC rebels escalated following the Wednesday killing of 11 army soldiers in a clash with the left-wing militias.

"We are running out of patience. We have to set a deadline for this process. Your willingness for peace must be proven by facts and not just words," he said.

The president made the statement during a speech at the end of the welcoming ceremony for South Korean President Park Geun-hye, who began her official visit to Colombia on Friday.

The Colombian government and the FARC are holding since 2012 peace talks in the Cuban capital, Havana.