The three powers once again called for an “immediate and unconditional ceasefire”.
Together, Paris, Moscow and Washington chair the Minsk Group of the Organisation for Security and Cooperation in Europe (OSCE) which, since 1992, has aimed to find a peaceful resolution to the conflict over Nagorno-Karabakh.
The former Soviet states of Azerbaijan and Armenia fought a bloody war over the mountainous region in the early 1990s with a truce declared in 1994, although there have been episodes of sporadic violence since.
The region lies inside Azerbaijan but has been under the control of ethnic Armenian forces backed by Armenia since the 1994 truce.
The latest flare-up of violence started on September 27 is one of the worst observed with dozens on both sides already killed in the fighting.
Azerbaijani authorities have not disclosed military casualties but said that 24 civilians have been killed and 121 have been injured in the nine days of fighting.
The state-run Armenian Unified Infocentre has tallied 21 civilian casualties and more than 200 military deaths.
On Monday, Armenia accused Azerbaijan of firing missiles into the region’s capital while Azerbaijan said several of its towns and its second-city were attacked.
In their joint statement, France, Russia and the US said they “condemned in the strongest possible terms the dangerous escalation of violence in and outside the Nagorno-Karabakh conflict zone”.
“The (Foreign) Ministers underline without reservation that the recent attacks which allegedly targeted civilian installations, both along the line of contact and in Azerbaijani and Armenian territories outside the Nagorno-Karabakh conflict zone, and that the disproportionate character of such attacks constitute an unacceptable threat to the stability of the region,” the statement also said.
Experts from Amnesty International called on both sides to refrain from using banned cluster munitions after analysing footage consistent with the use of such weapons in Stepanakert, the capital of Nagorno-Karabakh.
The NGO said the cluster munitions — which scatter hundreds of submunitions over a wide area many of which do not immediately explode — “appear to have been fired by Azerbaijani forces.”
“Cluster bombs are inherently indiscriminate weapons, and their deployment in residential areas is absolutely appalling ad unacceptable. As fighting continues to escalate, civilians must be protected, not deliberately targeted or recklessly endangered,” Denis Krivosheev, Amnesty International’s head of Eastern Europe and Central Asia, said.
Azerbaijan President Ilham Aliyev said Armenia’s withdrawal from Nagorno-Karabakh is the sole condition for a cessation of hostilities.
Armenia, meanwhile, alleges that Turkey is involved in the conflict by providing military support to Azerbaijan. Prime Minister Nikol Pashinian said that “a cease-fire can be established only if Turkey is removed from the South Caucasus.”
NATO member Turkey has denied sending weapons or foreign fighters but President Recep Tayyip Erdogan has said Ankara will stand by Azerbaijan until it reaches “victory”.
Jens Stoltenberg called on Turkey on Monday during a meeting with Erdogan to “use its considerable influence to calm tensions.”
“We are deeply concerned by the escalation of hostilities. All sides should immediately case fighting & find a way forward towards a peaceful resolution,” he added.