Serbia's negotiations on EU membership began in earnest on Monday with the opening of the country's first two accession chapters in a move aimed at rewarding Belgrade for improving relations with Kosovo, dpa reported. Serbia and its erstwhile breakaway province have made important progress towards normalizing their relations, following a brief war in 1999, during years of talks overseen by the European Union. Both have been offered closer EU ties in return. "This opening is a decisive step towards the EU," said Luxembourg Foreign Minister Jean Asselborn, whose country holds the rotating EU presidency. It would not have been possible without the "courageous decisions" taken by Belgrade, he added. "This is an important and big day for us, one of those days when we are writing the pages of our history," said Serbian Prime Minister Aleksandar Vucic, following talks in Brussels. "We do not have to dream dreams any more about the EU. All we have to do is work hard." The chapters opened Monday cover financial control and the delicate issue of relations between Serbia and Kosovo, whose independence Belgrade does not recognize. They are two out of 35 areas in which Serbia must fall in line with EU law. Vucic has pledged to meet all of Brussels' membership requirements by 2019.