BELGRADE, Sept 13 (Reuters) - Western Balkan states have a long way to go to achieve membership in the European Union but it is Germany"s goal that they do, Chancellor Angela Merkel said on Monday. At a joint news conference in Belgrade with Serbian President Aleksandar Vucic, Merkel said it was in the geostrategic interest of existing EU members that the Western Balkan states join the bloc. "There is still a long way to go before Serbia and the whole region can finally become members of the European Union, as is our common goal," Merkel said. "We, who are already members of the European Union, should keep in mind that there is an absolute geostrategic interest for us to include these countries in the European Union." Merkel has previously said she sees the six Western Balkan states - Serbia, Albania, Northern Macedonia, Bosnia-Herzegovina, Montenegro and Kosovo - as future members of the EU.