General view of Montenegro’s parliament during a discussion on NATO membership agreement in Cetinje Thomson Reuters Montenegro's parliament on Friday supported the Balkan country's membership in NATO in a historic turn toward the West amid protests by Russia and the pro-Russia opposition.

Lawmakers voted 46-0 in the capital of Cetinje to ratify the accession treaty with the Western military alliance. They then stood up and applauded the decision.

The parliament has 81 members, but pro-Russia opposition lawmakers boycotted the session. Several hundred opposition supporters gathered outside the hall before the vote.

Montenegro has a small military of around 2,000 troops, but it is strategically positioned to give NATO full control over the Adriatic Sea. The other Adriatic nations — Albania, Croatia and Italy — already are in the alliance.

Russia has been angered by NATO's expansion to Montenegro, which is in Moscow's traditional area of interest. Montenegro has accused Russia of being behind a foiled Election Day coup in October allegedly designed to throw the country off its path toward NATO. Russia has denied the accusation.

Prime Minister Dusko Markovic told lawmakers that NATO membership was a guarantee for Montenegro's future security, economic progress and regional stability.

"This assembly and its members have a historic privilege to make a decision that will be remembered as long as there is Montenegro and Montenegrins," Markovic said. "This day will be marked among the brightest in our history."

Markovic's predecessor, Milo Djukanovic, who was the head of government during the alleged coup attempt that reportedly included plans for his assassination, said joining NATO was the most important decision in recent history.

Montenegrin Prime Minister and leader of ruling Democratic Party of Socialists, Milo Djukanovic, casts his ballot at a polling station in Podgorica Thomson Reuters

"After long suffering and roaming through history, (Montenegro) is finally in the position where it logically, historically, civilization-wise and culturally belongs," Djukanovic said.

Anti-NATO demonstrators chanted "Treason!" and "Thieves!" and burned a NATO flag during the protest outside parliament before peacefully dispersing. A banner read: "NATO murderers, your hands are bloody!"

"I feel humiliated because others are making a decision in my name," former Montenegrin President Momir Bulatovic said. "What is happening now is triumph by force and lies!"

Opposition leaders said they don't recognize the parliamentary ratification of the NATO accession and will call a referendum on the issue, if they come to power in the future.

The country of 620,000 has been historically divided between pursuing pro-Western policies and sticking to an alliance with Orthodox Christian allies Serbia and Russia.

Both Russia and the pro-Russia opposition in Montenegro also have evoked the NATO bombing of Yugoslavia in 1999 —which included Serbia and Montenegro at the time — as a reason to stay out of the alliance.

U.S. soldiers attend welcoming ceremony for U.S.-led NATO troops at polygon near Orzysz Thomson Reuters

Markovic said Montenegro was drawn into Serbia's war with NATO and that membership in the alliance would help prevent anything like that from happening again.

"NATO and the EU have always been and remain a guarantee of stability and security and cooperation and the main basis for peace in Europe," Markovic said. "It is about what kind of future we choose for us and generations to come," he said.

Montenegro was formally invited to join NATO in December 2015. Markovic said 27 out of 28 NATO member states have ratified Montenegro's entry protocol and Spain would do so in the coming weeks.

Montenegro gained independence from Serbia in 2006.