FILE PHOTO: The Spanish flag flies at the Gibraltar-Spain border, in front of the Rock in the British overseas territory of Gibraltar, historically claimed by Spain, in La Linea de la Concepcion, southern Spain, November 15, 2018. REUTERS/Jon Nazca/File Photo

BRUSSELS (Reuters) - The 27 European Union leaders on Sunday aim to endorse a separate declaration along with the Brexit package to cover fisheries, environmental standards and Gibraltar, EU diplomats said.

These three areas are outstanding in what will form a Brexit package put forward for the leaders’ approval on Sunday - a legal divorce treaty and a political declaration on EU-UK future ties.

The separate declaration would be a statement by the 27 remaining EU states only and would not be negotiated with Britain, the sources added.