German Deputy Foreign Minister Gernot Erler said on Tuesday the European Union could not admit countries such as Croatia and Macedonia unless it resolves the issue of a European constitution, Reuters reported. "We simply have to see that without a resolution to the constitution issue, it will not be possible to take in all the countries that are already in the (accession) process, that are standing before the door," Erler told a German radio station. But Erler said the accession of Romania and Bulgaria was a "done deal" that should be completed before Germany takes over the rotating EU presidency on Jan. 1, 2007. He welcomed current EU president Austria's expressed intention to make progress in forging a closer relationship between the EU and southeastern Europe. "I'm very pleased that the Austrian presidency has stated as a goal that it wants to make progress in southeastern Europe, in the Balkans. This means there's a good chance that by the time the German presidency begins many issues will be further along." Romanian and Bulgarian membership will take the number of EU states to 27, the maximum number provided for by the Treaty of Nice which now governs the bloc. The treaty stipulates that member states must then agree to reduce the size of the executive European Commission to fewer than 27 members. France has also warned that without a constitution, other candidates and EU hopefuls would be in limbo. The EU admitted 10 mostly former communist countries in central and eastern Europe to the bloc in 2004, taking membership to 25. Croatia and Turkey have begun accession talks and Macedonia was accepted as a candidate for membership last month. Bosnia, Serbia and Montenegro, and Albania would also like to join.