Russia on Thursday accused Armenia of trying to rupture increasingly strained ties between the two ex-Soviet countries, as Yerevan voices mounting criticism of Moscow's role as regional security guarantor.

The small Caucasus nation has been in a decades-long standoff with its neighbour and rival Azerbaijan, and has repeatedly accused Moscow of not coming to its aid when tensions boiled over into war in 2020.

"The Armenian leadership, under far-fetched pretexts and by twisting the history of the last three or three and a half years, is deliberately pursuing a course towards the collapse of relations with the Russian Federation," Foreign Minister Sergei Lavrov said in an interview with Russian media.

Yerevan has recently floated the possibility of leaving the Russian-led Collective Security Treaty Organisation (CSTO), a security bloc that includes a handful of former Soviet countries.

Armenian Prime Minister Nikol Pashinyan described his country's security alliances as "ineffective" after Azerbaijani forces last September stormed Nagorno-Karabakh, territory internationally recognised as part of Azerbaijan but until then controlled by ethnic Armenian separatists.

Russian peacekeepers had been stationed around the territory following a 2020 war between the two countries.

Armenia boycotted a CSTO summit at the end of 2023 over what Pashinyan described as the bloc's failure to fulfil its security obligations.

In a sign of its ambition for new security guarantees, Yerevan has been forging partnerships with Western countries -- mainly France and the United States.

bur/imm