Officials in Brussels on Friday urged Slovenia and Croatia to resolve a border dispute that is preventing Zagreb from advancing on its path towards European Union membership, according to dpa. "Let us all try to calm down, have a good Christmas break and immediately after start thinking about how we can get out of this," EU Enlargement Commissioner Olli Rehn said after a meeting in Brussels with Croatian Foreign Minister Gordan Jandrokovic. Slovenia is blocking Croatia's membership talks because of a neighbourly dispute over a stretch of water in the Adriatic Sea. Slovenia, which joined the EU in 2004, wants the border drawn in such a way that will allow its vessels direct passage to international waters. But Croatia is dividing the Bay of Piran evenly between itself and Italy, thus blocking Slovenian access to the high seas. "We are ready to find a solution," Jandrokovic said. "We cannot let bilateral issues interfere with our accession process." During the talks in Brussels, Croatia and the European Commission opened one new pre-accession negotiating chapter, on public procurement, and closed a further three, raising the total number of open chapters to 22 out of 35. Zagreb had hoped to open as many as 10 new chapters on Friday. Croatia aims to become the 28th member of the EU in 2010 or 2011.