Officials from Mexico, the United States and Cuba met on Thursday for a second round of talks on the limits of the Western Polygon, an oil-rich area in the waters of the Gulf of Mexico, two people close to the discussion said.
Talks about who owns what is in the so-called "Doughnut Hole" were prompted after Cuba and the United States announced they would restore diplomatic ties in late 2014.
International law gives countries the right to any resources found in the sea within 200 nautical miles of their territory. But when areas overlap, as they do in the case of the resource-rich Doughnut Hole, countries have to craft an agreement.
The talks would conclude on Friday, one of the sources said, noting that the officials aimed to define the coordinates to define where the respective limits lie.
A Mexican government spokesman confirmed officials from the three countries met to try and make progress on the issue and that results of the meeting would be made public on Friday.