Nicaragua on Thursday filed proceedings with the UN's highest court against Costa Rica over a road near their disputed border that they say is causing serious environmental damage.

"Nicaragua contends that Costa Rica is carrying out major construction works along most of the border area between the two countries with grave environmental consequences," the International Court of Justice said in a statement.

"Costa Rica's unilateral actions... threaten to destroy the San Juan de Nicaragua River and its fragile ecosystem, including the adjacent biosphere reserves and internationally protected wetlands that depend upon the clean and uninterrupted flow of the River for their survival," said Nicaragua's application, quoted by the ICJ.

The application lists a number of degradations such as the dumping of sediments in the river and the felling of trees.

Managua says it decided to take the matter before the UN court because Costa Rica had violated Nicaragua's territorial integrity and demands its neighbour be forced to cease construction and pay for damages.

The ICJ in March issued a ruling on another border spat urging the two neighbours to refrain from deploying or maintaining any military or civilian personnel in a disputed area.

Some observers say the two countries' apparant willingness to file complaints at the ICJ represents a cynical intent to score political points against each other.