Armenian Prime Minister Nikol Pashinyan called on Wednesday for the country to change its constitution, a move demanded by Azerbaijan that could facilitate a peace treaty between the longtime rivals.

"The adoption of the new constitution by a national referendum is essential," Pashinyan said during a televised address, adding that the current document lacked legitimacy.

He did not set a date for a referendum nor specify what would be contained in a new draft of the constitution.

Azerbaijan, with which Armenia has been locked in conflict for more than three decades, says Armenia's current constitution makes implicit claims on its territory, something Yerevan denies.

Armenia and Azerbaijan have since the late 1980s fought intermittently over Nagorno-Karabakh, an Azerbaijani region with a mostly Armenian population.

In September 2023, Azerbaijan retook Nagorno-Karabakh, ending three decades of de facto independence of the territory, and prompting almost all of its 100,000 ethnic Armenians to flee to Armenia.

Though the two sides have since both said they want to sign a treaty to formally end the conflict, talks have been fitful and progress has been slow.

The countries have no formal diplomatic relations, and their 1000 km (620 mile) shared border remains closed and heavily militarised.

Azerbaijani President Ilham Aliyev in January accused Armenia of posing a "fascist" threat that needs to be destroyed, in comments that Armenia called a possible attempt to justify fresh conflict.