Chile excluded Bolivian diplomats from a visa-free arrangement for Bolivians late on Tuesday in a row over several Chilean ports along the Pacific coastline.

Chilean Foreign Minister Heraldo Munoz said in the future Bolivian diplomats would have to apply for entry visas and display them in their passports.

This follows a visit earlier this week by his Bolivian counterpart David Choquehuanca to the Chilean ports of Arica and Antofagasta to press a Bolivian demand that it retain freedom of transit for its exports under a treaty dating back to 1904.

The ports lie in an arid but mineral-rich zone in northern Chile, bordering with Peru to the north.

Bolivian President Evo Morales reacted to Munoz's visa restriction by warning that "bitter animosities" could lead to a new diplomatic crisis.

Bolivia and Chile have had no formal diplomatic relations since 1978.

Last week, Chile filed papers at the International Court of Justice in The Hague rejecting Bolivians' claim for sea access.

And, recently, Chile opened a new case before the court over the river Silala. Bolivia wants fees for river water diverted into Chile's Atacama desert.

Atacama is the site of a major Chilean wind power project, launched last year. Its 56 turbines are due to be operating by next year.

ipj/kms (AFP, dpa, epd)