A Turkish F-16 fighter jet shot down an Armenian SU-25 warplane over Armenian territory today, killing the pilot, an Armenian defence ministry spokeswoman said.

Shushan Stepanyan, an Armenian defence ministry spokeswoman, wrote on her Facebook page that the plane had been on a military assignment when it was shot down.

Fierce fighting has been raging in recent days between Azerbaijani and Armenian forces.

Armenia and Azerbaijan have been locked in a territorial dispute over the ethnic Armenian region of Nagorny Karabakh for decades, with deadly fighting flaring up earlier this year and in 2016.

Turkey is "fully ready" to help Azerbaijan take back its separatist region of Nagorny Karabakh, President Recep Tayyip Erdogan's top press aide said earlier today ahead of a UN Security Council debate on the crisis.

The comments followed a call from Russia for Turkey, which views Azerbaijan as its close ally and Armenia as its historic foe, to stop proclaiming support for Azerbaijan and to work toward a diplomatic solution to the escalation, the deadliest since 2016.

"Turkey will be fully committed to helping Azerbaijan take back its occupied lands and to defending their rights and interests under international law," Fahrettin Altun tweeted.

Turkey hoped the UN meeting "will establish a strong foundation for a solution", he added.

Mr Altun said Turkey stood by Azerbaijan "completely", adding: "Let there be no doubt that the world will hear our roar if Azerbaijan were to suffer from the slightest injustice under international law."

Read more: Far away conflict or 'Europe's next avoidable war'?

Armenia has accused Turkey of sending mercenaries to back Azerbaijani forces in the ethnically Armenian region, which Ankara has officially denied.

Mr Altun in turn accused Armenia of violating the Geneva Conventions in the border region, praising Azerbaijan for "observing international law to the letter".

"We call on global players to approach this matter from the perspective of fairness," he said.

"The world cannot afford to equate the aggressor with the aggrieved party in the name of the so-called principle of neutrality or to preserve the political balance of power," Mr Altun said.