The two countries have been at odds for decades over the Nagorno-Karabakh region, which in Soviet times had a majority Armenian population but was legally part of Azerbaijan.

After the collapse of the Soviet Union, Nagorno-Karabakh declared independence from Baku as the Artsakh Republic, with support from Yerevan, sparking a three-year war.

The war ended in 1994 with an Armenian victory, and Nagorno-Karabakh was under Armenian control for a quarter of a century, although its status was never internationally recognized.

After a decade of stagnation, Azerbaijan recaptured large parts of the region in 2020, forcing Armenia to make major territorial concessions. This included a provision limiting Armenia’s access to the region to a safe corridor monitored by Russian peacekeepers.

Meanwhile, the truce was broken several times by sporadic attacks from both sides.