The Russian president said Moscow was concerned about the sudden eruption of violence and that he believes the immediate goal is to cease hostilities, the Kremlin said in a statement. The phone call between Putin and Pashinyan was made on the latter's initiative.
Earlier in the day, Russian Foreign Minister Sergey Lavrov called both his Azeri and Armenian counterparts to express Moscow's concerns and urge them to step back from the conflict.
Speaking to Putin, Pashinyan stressed that third parties from outside of the region should not get involved in the situation, according to the Armenian side.
Pashinyan himself had earlier rebuked Turkey, a long-time ally of Azerbaijan, for interfering in the situation. Ankara voiced support for Baku in the unfolding stand-off and blamed Yerevan for the violence.
Hostilities between Azerbaijan and the ethnic Armenian Nagorno-Karabakh erupted after Azeri forces launched an offensive on Sunday morning. Baku said it was responding to shelling of its forces, but Yerevan rejected this justification, accusing its opponent of breaking a ceasefire.
The region, where the population is predominantly Armenian, broke away from Azerbaijan in the late 1980s, and relies on military and economic support from Yerevan. Amid the flareup, both Azerbaijan and Armenia imposed martial law and voiced their determination to fight on.
Russia is part of the mediation group of the Organization for Security and Cooperation in Europe (OSCE), working to tone down tensions between Azerbaijan and Armenia and negotiate a peaceful resolution to their dispute over Nagorno-Karabakh. However, Moscow is also treaty bound to defend Yerevan via the CSTO, an Russian-led alternative to NATO.