Company official Juan Carlos Restrepo told Reuters that even last weekend had obstacles in the form of disruptions from indigenous groups that blocked a rail line.

The blockade, which lasted from Saturday afternoon until Sunday morning, did not interrupt any logistics but Restrepo noted that repeated disruptions would make Cerrejon’s target harder to attain.

“We have had with the strike, blockages and attacks, a number of interruptions to the supply of coal,” he said.

“We are able to recover some of the lost time but with more things happening … it gets harder to reach it.”

Still, Restrepo said, Cerrejon was “optimistic” about its chances to reach the 34Mt goal.

The company, which is a joint venture between Anglo American, BHP Billiton and Glencore Xstrata, produced 34.6Mt last year of the nation’s 89.2Mt total.

The Andean nation’s government has forecast 94Mt for whole-year 2013 across Colombian coal.

However, Cerrejon and other miners have spent much of the year overcoming various issues including worker strikes, export ship stoppages and two bombings of Cerrejon’s railway in October that officials believe were the work of FARC guerrillas.

Colombia is the world’s fourth-largest coal exporter; much of its output is utilised by the European market.