The European leaders want to reform the border-free Schengen traty after a surge in migrants from North Africa Italian Prime Minister Silvio Berlusconi and French President Nicolas Sarkozy issued a joint call on Tuesday for changes to the EU\'s open-border treaty after a row over thousands of Tunisian migrants. \"We both believe that in exceptional circumstances there should be variations to the Schengen treaty on which we have decided to work together,\" Berlusconi said at a news conference after the summit. Sarkozy said France and Italy had issued a joint letter to European Union leaders calling for reform of the treaty.