The small Balkan nation is on its way to become the 29th member of the US-led military alliance after the US Senate ratified its accession on Tuesday.
“Montenegrin succession to the NATO family of democratic nations will contribute to the stability of the region and the whole of Europe and I expect all nations to fully complete ratification in June,” Stoltenberg said.
Once all member states have ratified the protocol, Montenegro will be invited to accede to the North Atlantic Treaty. It was formally invited to join the bloc in December 2015.