(ANSA) - UDINE, 06 MAG - BRUSSELS, MAY 06 - At the informal summit in Porto, EU leaders will address the Russia dossier after the diplomatic crisis with the Czech Republic and the concentration of troops along the border with Ukraine. EU sources reported. "I expect the leaders to address these issues: there have been so many events that it is not possible to wait until the strategic discussion on EU-Russia relationship planned for the summit at the end of the month," said the EU source. (ANSA).