(ANSA-AFP) - BRUSSELS, 04 NOV - The EU said Wednesday that Montenegro was "on track" to join the bloc in 2028, and urged Ukraine to speed up reforms if it wanted to wrap up membership talks in two years. Russia's invasion of Ukraine has breathed fresh momentum into efforts to expand the 27-nation European Union. Leading the pack of would-be members are Montenegro, Albania, Ukraine and Moldova. In its annual review of enlargement efforts Brussels set out roadmaps for the four hopefuls. EU enlargement chief Marta Kos said that Montenegro and the EU could sign an accession treaty "at the earliest" in June next year -- after which it would need to be ratified by the 27 member states. "Montenegro is on track to become the 28th member of the European Union in 2028," she said. One potential obstacle for the Western Balkan nation of some 650,000 is a string of outstanding issues with neighbour Croatia. But EU officials are hoping for progress in those negotiations and that the path can be cleared for Montenegro. Albania and Moldova are then seen as closest behind -- with Brussels expecting both to make strides in 2027. (ANSA-AFP).