Colombia on Wednesday more than doubled the size of a huge nature reserve as it fights to protect the Amazon from deforestation.

Environment Minister Juan Gabriel Uribe said deforestation of the Colombian Amazon is a worrisome problem, mainly because of land being cleared for growing coca leaves, logging, illegal mining and agriculture.

With the increase, the Chiribiquete nature reserve now sprawls over 2.8 million hectares (6.9 million acres), making it the biggest of the South American country's 58 natural parks. Altogether, they total about 14 million hectares.

Colombia is one of nine countries that share a piece of the Amazon. Its portion is 6.3 percent of the total. The lion's share is Brazil's, at 64 percent.

Colombian President Juan Manuel Santos said the enlargement of the Chiribiquete nature reserve was aimed at preserving "life, sustainability and the well-being of the Colombian people and humanity."

Colombia committed to the step last year at an international environmental summit.

Uribe said the enlargement of the reserve is key to preserving the Amazon.

"The park is located deep in the heart of the Amazon, which is the world's lung, so we are sending a message about the importance of that region," Uribe told AFP.