Armenia has appealed to a Russia-led security bloc after accusing Azerbaijani troops of crossing its border and trying to claim territory.
Prime Minister Nikol Pashinyan’s office said he had made a formal request for the Collective Security Treaty Organisation (CSTO) to hold consultations on supporting member Armenia.
Under the treaty, members of the bloc, which also includes Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan, consider aggression against one member as aggression against them all.
Armenia on Thursday accused Azerbaijan’s military of crossing the southern border in an “infiltration” to “lay siege” to a lake that is shared by the two countries. Azerbaijan rejected the claims.
Western countries including the United States and France raised concerns, with tensions still high after last year’s war between the longtime rivals over the disputed region of Nagorno-Karabakh.
The six-week conflict claimed some 6,000 lives and ended after Armenia ceded swathes of territory it had controlled for decades.
Pashinyan informed Russian President Vladimir Putin of his decision to turn to the CSTO during a phone call late Thursday, his office said.
“The Russian side reaffirmed its readiness to continue exerting active mediation efforts with a view to ensuring stability in the region,” it said.
The two “agreed that the situation should be settled by getting Azerbaijani troops back to their starting positions.”
The Kremlin said Putin was calling on both countries to respect peace agreements, adding that Russia would continue “active mediating efforts”.
Putin’s spokesman Dmitry Peskov said Pashinyan had not asked for immediate assistance.
“The Armenian side expressed extreme concern over the situation at the border,” Peskov said. “President Putin shared this concern.”
Azerbaijan has called Pashinyan’s claims provocative, saying its “border troops are taking positions that belong to Azerbaijan, in the Lachin and Kalbajar districts.”
Armenia, which had controlled Lachin and Kalbajar since the 1990s, handed the districts back to Azerbaijan last year under a Russian-brokered ceasefire agreement that ended the fighting.
Ethnic Armenian separatists declared independence for Nagorno-Karabakh and seized control of the mountainous enclave and several surrounding regions in a war in the 1990s that left tens of thousands dead and forced hundreds of thousands from their homes.
After last year’s conflict they retained control of most of Karabakh itself, with Russian peacekeepers deployed between the two sides.