NATO’s leader on Wednesday said Montenegro's accession to the alliance is complete and the Balkan country will join at Thursday's leaders’ meeting.
Speaking a day before a NATO summit in Brussels, Secretary-General Jens Stoltenberg said all the alliance's members had ratified the small Balkan state’s membership.
"Prime Minister Markovic of Montenegro will join us tomorrow. The parliaments of all 28 Allies and Montenegro have now ratified the country’s accession to NATO," Stoltenberg said.
"This is a step forward for Montenegro, for stability in the Western Balkans and for our vision of a Europe whole, free and at peace. We look forward to formally welcoming Montenegro as our 29th ally in early June."
However, Russia, in particular, has been critical of Montenegro's NATO moves.
Last month, Russia's Foreign Ministry said: "We view this step as a sign of inertia in Washington’s policies and a reflection of the logic of confrontation in Europe, where new dividing lines are being drawn."
Moscow said the effort to involve the Balkan state in NATO "disregarded" the real opinion of Montenegro’s people.
"We regard the policy of including Montenegro in NATO as profoundly erroneous," it added.