Colombia's government says it has made its biggest-ever seizure of cocaine, uncovering at least 20 metric tons of the drug along the country's Pacific coast.

Colombian Defense Minister Juan Manuel Santos says the cocaine was found Sunday in about 1,000 packages buried near the town of Francisco Pizarro.

Colombia is the world's biggest producer of cocaine. Much of the drug leaves Colombia by sea for Mexico, where it is then smuggled overland into the United States.

Washington has provided Colombia with billions of dollars in military aid to fight the drug trade in recent years. Colombian President Alvaro Uribe visits Washington Tuesday, to try to maintain U.S. support for his anti-drug program.

Some information for this report was provided by AP and Reuters.