MADRID, April 10 (Xinhua) -- The countries of southern Europe on Monday reaffirmed their commitment to work together for a strong and united European Union in the Declaration of Madrid signed here.

Spanish Prime Minister Mariano Rajoy along with leaders from France, Greece Italy, Portugal, Cyprus and Malta discussed the future of the EU in the post-Brexit era.

Rajoy expressed "the need for the unity of the 27," while saying he would support the negotiation process where it was vital to "preserve the rights of European citizens."

French President Francois Hollande said it was "important to have a common position." He spoke of the need to "quickly deal with the rights of the EU citizens who live in the UK and of British citizens who live in Europe."

Maltese leader Joseph Muscat said it was important to ensure neither European nor British citizens were "used as bargaining chips in the negotiations."

Portuguese leader Antonio Costa said the leaders wanted "as close a relationship as possible with the UK."

Other topics on the agenda at the Madrid Summit included security and closer fiscal ties.

"Decisive progress should be made on the completion of the economic and monetary union, in line with the Rome Declaration. We call on the swift completion of the banking union, including by the creation of a European deposit insurance system," the post-summit statement said.

The Madrid Declaration also stressed the need for "cooperation between enforcement agencies, which is crucial between European Union countries and if necessary with third states."