The President of Bolivia Evo Morales criticized neighboring Chile over an increase in export rates in the port of Antofagasta.
The reaction came after executives of Antofagasta told Bolivian exporters they would increase tariffs and other measures that limit the trade of Bolivian cargo through the Chilean port.
The president said it was an "unfair and discriminatory decision" since Chile is violating a 1904 treaty that was signed to lower the cost of Bolivian imports.
"A state that does not respect treaties is a state that ignores international law," Morales said.
Bolivian Foreign Vice Minister Juan Carlos Alurralde said it the move is "a flagrant violation to international law," adding that the Chilean government has imposed "requirements for advance payments and even require bank guarantees to provide services."
According to Alurralde the tax rate for Bolivian cargo in Chile's port was US$1.87 per ton in 2004, but last year it grew to US$ 7.64.
Meanwhile, through his Twitter account Morales added that the governments of Chile "historically have not respected, nor respect its neighbors."
The Bolivian leader was likely referring to the maritime border dispute that has resulted in historic tensions between the two countries.
In recent years, Bolivia has presented several legal arguments to the International Court of Justice over its bid to recuperate sovereign access to its former Pacific coast, which was lost to neighboring Chile in the 1879 War of the Pacific.
The Bolivian government hopes to gain sovereign access to the Pacific Ocean in order to import and export goods and raw materials without paying costly tariffs to neighboring Chile and Peru.