Serbian Defense Minister Aleksandar Vulin signed a note Wednesday that finalized the nation’s accession to EU’s Greek-led battlegroup, the Greece military chief has said in a statement.

“This event bears double significance. Regional unity will help us protect our countries more efficiently while bolstering Serbia’s link to events in the sphere of European defense,” Defense Minister Panos Kammenos said.

The battlegroup also includes Bulgaria, Romania, Cyprus and Ukraine. Minister Vulin said earlier this month Serbia’s participation in the group, starting in 2020, would help it align defense and national security capabilities with EU military guidelines.