Lawyers for Chile's government argued Thursday that judges at the United Nations' highest court should reject a request by Peru to draw a maritime boundary between the two countries, arguing the boundary was settled in a 1952 treaty.
Peru argued earlier this week that a maritime boundary between the Andean neighbors was never established and that two agreements which Chile claims set the border are nonbinding and merely denoted some fishing zones.
The Peruvian government wants the International Court of Justice to set a border that would give Peru sovereignty over a far larger part of the Pacific Ocean than it currently controls.
But Chile representative Albert van Klaveren Stork urged the world court to reject the request.
"All boundary issues between Chile and Peru have been settled for many decades," he said, adding that in two days of legal arguments and lengthy written submissions, Peru "fails to provide any evidence that the all-purpose maritime boundary is instead a provisional fishing arrangement."
Chilean President Sebastian Pinera on Thursday called his country's position on the boundaries "solid and convincing." Pinera said the limits between Chile and Peru were set 60 years ago through the 1952 and 1954 treaties.
Fishing rights are at the core of the dispute.
Chile and Peru are among the world's top producers of fishmeal, and the waters off their coasts are an important source of income for both countries. If Peru wins, it could gain control over more than 60,000 square kilometers (23,000 square miles) of ocean that Chile has controlled for the past 60 years.
That control underpins Chile's arguments that the border has been accepted by both sides for years, Van Klaveren Stork said.
"Chile has submitted abundant evidence to the court showing the use, and respect of the boundary parallel for numerous purposes ranging from the laying of submarine cables to fisheries enforcement to air space," he added. "Peru had ample opportunity to object to Chile's actions, yet it never did."
The Peruvian government's lawyer, Alain Pellet, told the court Monday there is "a flagrant lack of any maritime delimitation" between the two countries.
Pellet said Peru wants the 16-judge court to draw a line that will equally divide the sea off the two countries' coasts based on established international law. "Peru asks neither more nor less than the laws of the sea grant to all coastal states," he said.
Hearings are continuing. Judges will likely then take months to reach a decision on the boundaries.
Associated Press writer Luis Henao contributed to this report from Santiago, Chile.