Turkey, a longtime ally of Azerbaijan, has accused Armenia of committing war crimes after reports it has been targeting civilian territories in the fight over occupied Karabakh.
Azerbaijan's President Ilham Aliyev has said in an interview on Monday on TRT that Turkey must be involved in the solution process for the Nagorno-Karabakh region after a potential future ceasefire.
Both Turkey and Azerbaijan have accused Armenian forces of targeting civilians in recent tensions on the Azerbaijan-Armenia front line
"A peace process will surely be started. Clashes cannot go on forever, so the sooner the better," Aliyev said on TRT Haber, the Turkish broadcaster.
Fighting between Armenia and Azerbaijan over the occupied Karabakh region entered the ninth day. Hundreds of people have been killed in the fiercest clashes in the region for more than 25 years.
"Armenia directly targets civilians [in Azerbaijan], which is essentially a war crime," said Turkish Foreign Minister Mevlut Cavusoglu after meeting with NATO Secretary General Jens Stoltenberg in the capital Ankara on Monday.
Stoltenberg is expected to meet Turkish President Recep Tayyip Erdogan later during the trip.
NATO is "deeply concerned" over the Upper Karabakh conflict, and called for the peaceful solution of the dispute, Stoltenberg said.
Hikmet Hajiyev, aide to President Aliyev, tweeted that Armenian forces attacked “densely populated civilian areas" in Ganja, Barda, Beylagan and other towns “with missiles and rockets."
Armenia denied the accusations.
NATO chief calls for ceasefire
Stoltenberg has also called for a ceasefire in occupied Karabakh as the death toll rose during fighting in the breakaway enclave in the South Caucasus.
"It is extremely important that we convey a very clear message to all parties that they should cease fighting immediately, that we should support all efforts to find a peaceful, negotiated solution," Stoltenberg said during a visit to Turkey.
"There is no military solution," he told a news conference on Monday.
Aliyev said a ceasefire could only be possible if Azerbaijan received international guarantees and a "concrete timeline" from Armenia on withdrawing its troops.
"We don't have eyes on any other country's lands, but what is ours should be ours," he said.
Aliyev said Armenia is dragging Russia into war by attacking Azerbaijan.
'Armenia must withdraw' from occupied lands
Turkey's Defence Minister Hulusi Akar said that Armenia must withdraw from the Azerbaijani territories it occupied and stop cooperating with terrorist organisations.
"Armenia must withdraw from the [Azerbaijani] territories it occupied, end cooperation with terrorist organizations, and get rid of mercenaries and terrorists from the [Upper Karabakh] region," Akar said in a virtual conference with Turkey's high-rank military officials.
By targeting civilians, Armenia is committing a "war crime" in the occupied Azerbaijani territory of Upper Karabakh, which should be known by everyone, he added.
Armenian authorities, who are openly targeting innocent civilians, will surely be judged by the conscience of humanity, particularly of their own people, he added.
Relations between the two former Soviet republics have been tense since 1991, when the Armenian military occupied Upper Karabakh, an internationally recognised territory of Azerbaijan.
Multiple UN resolutions, as well as many international organisations, demand the withdrawal of the invading forces.
The OSCE Minsk Group, co-chaired by France, Russia and the US, was formed in 1992 to find a peaceful solution to the conflict, but to no avail. A ceasefire, however, was agreed upon in 1994.
The fighting began on September 27 and has surged to its worst level since the 1990s, when some 30,000 people were killed.
Many world powers, including Russia, France and the US, have urged an immediate ceasefire.
Turkey, meanwhile, has supported Baku's right to self-defense.