Havana, Cuba (CNN) -- Spanish oil company Repsol is in "the exploration stage" of oil drilling off of Cuba's northern coast, prompting a controversy in south Florida over fears of a potential spill.
The company is part of a consortium that includes Norwegian oil and natural gas company, Statoil. Repsol will begin an appraisal of the project following the construction of a drilling rig that's being built in China, Kristian Rix, a company representative told CNN in a written statement.
The European oil giant first drilled near Yamagua, Cuba, in 2004 and found "encouraging results," Rix said.
But in the aftermath of BP's Deepwater Horizon disaster in the Gulf of Mexico, U.S. Sen. Bill Nelson, D-Florida, called on President Barack Obama to "prohibit the Cuban regime from initiating further drilling."
Though deepwater drilling has been largely banned off Florida's coasts, a 1977 treaty between the United States and Cuba divides the water between the two countries equally.
That would allow oil companies to drill in Cuban waters that lie just 45 miles from the Florida Keys.
The region is considered rich with natural resources, housing an estimated 4.6 billion barrels of oil and nearly 10 trillion cubic feet of natural gas in the North Cuba Basin, according to the U.S. Geological Survey.
But a nearly half-century trade embargo has traditionally stymied efforts to develop deep-water platforms and Cuban oil exploration.