LONDON (AP) — European Union diplomats are meeting to finalize the draft divorce agreement between Britain and the bloc, amid a warning from Spain that it will oppose the deal if it isn't guaranteed a say over the future of Gibraltar.

Spanish Prime Minister Pedro Sanchez tweeted that Britain and Spain "remain far away" on the issue and "if there are no changes, we will veto Brexit."

Spain wants the future of the tiny British territory at the tip of the Iberian Peninsula to be a bilateral issue between Madrid and London.

Spain doesn't have a veto on the withdrawal agreement, which does not have to be approved unanimously. But it could hold up a future free-trade deal between Britain and the EU, which would require approval of all 27 EU nations.

British Prime Minister Theresa May has said she has been clear in talks with Spain's leaders that British sovereignty over Gibraltar will be protected.

Britain insists Gibraltar is part of the United Kingdom, but Spain argues that it is not. Madrid has never dropped its claim of sovereignty over the rocky outcrop at the tip of the Iberian Peninsula.