(ANSA) - BELGRADE, JUN 15 - The EU has officially started accession talks with Ukraine. The first cluster, the Fundamentals cluster, was established at today's meeting in Luxembourg, following long-standing opposition in Budapest. "These days are difficult to describe. This is a historic day for both Ukraine and Europe. The opening of the first cluster is a critical and long-awaited milestone in Ukraine's accession process, as well as the EU's commitment to a united, peaceful, and democratic continent," said Marilena Raouna, Cypriot Deputy Minister for European Affairs, speaking on behalf of the EU Presidency. (ANSA).