European Union leaders are poised to come to a deal on Brexit this weekend in Brussels.

The deal — a document of more than 500 pages — would allow the U.K. a 21-month "transition period" before breaking off from the EU. Though the U.K. would formally withdraw in March 2019, it would remain under EU regulations throughout the transition.

EU President Donald Tusk says he'd "recommend that we approve on Sunday," even though "no one has reasons to be happy."

In a statement, Tusk wrote to the European Council, "During these negotiations, no-one wanted to defeat anyone. We were all looking for a good and fair agreement. And I believe that we have finally found the best possible compromise."

Spanish Prime Minister Pedro Sanchez previously expressed concerns about the future of Gibraltar, the British territory of less than 3 square miles on Spain's southern coast.

Those fears were quelled after Sanchez spoke with Tusk, and directly with British leaders, on Saturday.

British Ambassador to the EU, Tim Barrow wrote in a letter that the U.K. "will negotiate the future agreements implementing the Joint Political Declaration on behalf of all territories for whose external relations the U.K. is responsible to ensure an appropriate and beneficial future relationship with the EU."

British Prime Minister Theresa May said in Brussels, "We have worked through the withdrawal issues for Gibraltar in a constructive and sensible way."

Sanchez confirmed that a deal had been reached over the future of Gibraltar, according to the Associated Press.

Leaders will vote on Sunday. If the deal passes, it will head to the British parliament, where it awaits further opposition.

Copyright 2021 NPR. To see more, visit https://www.npr.org.