Azerbaijani and Armenian forces claimed to have inflicted heavy losses as fighting raged for a third day on Tuesday over Azerbaijan's breakaway region of Nagorny Karabakh.
Renewed US calls echoed by Germany and Russia for a halt to the fierce clashes that erupted Sunday went unheeded by the ex-Soviet rivals that have been locked for decades in a territorial dispute.
The UN Security Council was scheduled to meet Tuesday for emergency talks on the military escalation over the ethnic Armenian region, where the intense fighting has caused nearly 100 confirmed deaths.
Both sides said fighting was continuing on Tuesday, despite urgent international pleas for a ceasefire.
In bellicose televised remarks, Azerbaijan's President Ilham Aliyev vowed to continue fighting.
"If the international community is not capable of stopping Armenia's reckless dictator, then Azerbaijan will do it," he declared.
The Armenian defence ministry said separatists in Karabakh had repelled Azerbaijani attacks along the frontline and that "the enemy suffered serious losses in manpower".
It said Azerbaijan's military had suffered major losses since the clashes erupted, with nearly 50 drones and six helicopters downed, and 80 tanks destroyed.
While accusing Azerbaijan of escalating the conflict, Armenia threatened to use longer-range weapons with greater destructive power.
- 'Corpses and wounded troops' -
In Baku, officials dismissed claims by the separatists that Armenian-backed troops had regained control of territory they lost in Sunday's fighting.
Azerbaijan said its military had repelled an Armenian counterattack and destroyed an Armenian motorised column and an artillery unit and, later, an entire motorised infantry regiment.
Its forces "continued an offensive on the city of Fizuli," in the Karabakh region, "destroying four enemy tanks and an armoured vehicle and killing 10 troops," the defence ministry said.
"The enemy... asked for help to evacuate corpses and wounded troops" from the battlefield.
Azerbaijan also threatened to destroy Armenia's Russian-supplied S-300 long-range surface-to-air missile systems, which it said are being moved to Karabakh.
- Appeal to Turkey -
The fighting between majority-Muslim Azerbaijan and Christian Armenia is threatening to draw in Turkey and Russia -- the main powerbrokers in the Caucasus region -- which back opposing sides of the conflict.
Yerevan is part of a military alliance of former Soviet states led by Moscow and the Kremlin on Tuesday urged Turkey and the warring sides to pursue "a peaceful settlement of this conflict using political and diplomatic means."
Ankara backs Azerbaijan and has been accused of sending mercenaries from northern Syria to bolster Baku's army, while Turkish President Recep Tayyip Erdogan said Monday it was time for the longstanding dispute over Karabakh "to be put to an end".
Azerbaijan has not reported military casualties, but the Armenian separatist government has released footage from the battlefield showing what it said were the remains of Azerbaijani soldiers.
Armenian officials confirmed Tuesday the deaths of three more civilians, while Aliyev said civilian casualties on the Azerbaijani side reached 10 on Tuesday.
- Return to negotiations -
That brings the total confirmed deaths in the fighting to 99 -- including 84 separatist fighters and 15 civilians.
Observers to the conflict have urged the international community to ramp up efforts aimed at finding a political solution.
The UN Security Council meeting, which was formally requested by Belgium after France and Germany led a push for it to be added to the agenda, was to be held at 2100 GMT, diplomats told AFP.
German Chancellor Angela Merkel has "urgently called for an immediate ceasefire and a return to the negotiating table," her spokesman said, after she spoke with Aliyev and Armenian Prime Minister Nikol Pashinyan.
US Secretary of State Mike Pompeo also for an end to fighting and a return to negotiations "as quickly as possible".
Karabakh's declaration of independence from Azerbaijan sparked a war in the early 1990s that claimed 30,000 lives, but it is still not recognised as independent by any country, including Armenia.
Armenia and Karabakh declared martial law and military mobilisation Sunday, while Azerbaijan imposed military rule and a curfew in large cities.
Talks to resolve the conflict -- which emerged amid the 1991 collapse of the Soviet Union -- have largely stalled since a 1994 ceasefire agreement.
France, Russia and the United States have mediated peace efforts as the "Minsk Group", but the last big push for a peace deal collapsed in 2010.