"Putin called on both sides to urgently ensure a complete cessation of military hostilities and respect for the ceasefire," the Kremlin said in a statement after Putin spoke to the two presidents separately by telephone.
Putin voiced "serious concern" after four days of fighting killed at least 64 people in the the worst outbreak of violence over the territory since since an inconclusive truce in 1994.
Putin also underlined the need to restart internationally moderated peace negotiations that have failed to definitively end the bitter feud over the past two decades.
Armenian and Azeri forces said they had agreed a ceasefire to halt the fighting from 0800 GMT.
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The truce came after Azerbaijan's army claimed to have snatched control of several strategic locations inside Armenian-controlled territory, effectively changing the frontline for the first time since the 1994 truce.
Separatists backed by Yerevan seized control of mountainous Nagorny Karabakh, a majority ethnic Armenian region lying inside Azerbaijan, in an early 1990s war after the Soviet Union crumbled that claimed some 30,000 lives.
While ex-Soviet master Moscow has sold arms to both sides and treads a careful line between the two, it has a military alliance with, and base in, Armenia and far closer ties to Yerevan.