YEREVAN, Armenia — After more than two decades as part of a Moscow-led military alliance, Armenia has effectively suspended its membership as a result of a growing rift with Vladimir Putin's Russia.

Speaking to France24 on Friday, Armenian Prime Minister Nikol Pashinyan said that the Collective Security Treaty Organization (CSTO), a club of former Soviet nations, "hasn’t fulfilled its security obligations towards Armenia."

"This couldn’t have gone without consequences. And the consequence is that in practice we have basically frozen our participation in the CSTO," Pashinyan said, accusing Moscow of failing to intervene in a simmering conflict with neighboring Azerbaijan, which is not a member of the alliance.

Tensions came to a head in September when Azerbaijan launched an offensive to retake the Yerevan-backed breakaway region of Nagorno-Karabakh, sparking an exodus of its 100,000 Armenians. Moscow had stationed a peacekeeping force in the region that abandoned its positions ahead of the assault.

Days before that, Pashinyan told POLITICO that Moscow's mission had failed and "as a result of the events in Ukraine, the capabilities of Russia have changed," making it less willing or able to defend its partners. Armenia, he added, is now working with the EU and the U.S. to carry out a slew of democratic reforms and bolster its democracy.

The prime minister's latest comments come as French Armed Forces Minister Sébastien Lecornu visits Armenia on Friday to announce a package of new arms deals expected to include radar equipment and night vision goggles.

But despite also hosting an EU border mission, Armenia has thousands of Russian troops stationed in the country and its borders are controlled by Moscow's security forces. While Pashinyan has previously hinted that those arrangements with Russia could be ended, he warned "that is an entirely different legal-contractual framework" to Armenia's membership of the CSTO.

Responding to the statement later Friday, Kremlin press secretary Dmitry Peskov said that Armenia had not lodged any official notification of the decision. “It’s very important to understand the details here,” he went on, “and we hope our Armenian friends will explain everything to us.”

This story has been updated.