The UN's top court on Friday ruled that it had jurisdiction in a border dispute between Guyana and Venezuela that dates back more than a century, which has flared up again with the discovery of oil.
Caracas has been pressing a historic claim to Guyana's Essequibo region, which encompasses two-thirds of the former British colony, since US oil giant Exxon Mobil discovered crude off its coast in 2015.
Guyana maintains that valid land borders were set in 1899 by an arbitration court decision in Paris, a decision its South American neighbour Venezuela has never recognised.
In 2018 United Nations Secretary General Antonio Guterres referred the row to the International Court of Justice in The Hague, which rules on disputes between UN member countries.
Venezuela refused to accept that the court had a mandate to get involved, and has refused to attend any hearings so far.
But ICJ president Abdulqawi Ahmed Yusuf announced on Friday that judges had ruled by 12-4 that the court "has jurisidiction" in the dispute over the original 1899 ruling.
The decision means that the ICJ will now hold full hearings on the merits of the overall case.
Guyana is pressing ahead with plans to drill for oil in the disputed waters, with production expected to begin soon.
Venezuelan President Nicolas Maduro has accused Guyana of "unilaterally" bringing the territorial dispute -- the subject of a failed UN-sponsored attempt to broker a settlement in 2017 -- to international justice without its agreement.