Brussels will play host to senior envoys from long-term foes Azerbaijan and Armenia on Tuesday, after Baku's victory in breakaway Nagorno-Karabakh, the European Union said.
Simon Mordue, chief diplomatic advisor to European Council president Charles Michel, will chair the talks, Michel's spokeswoman said.
Azerbaijan and Armenia, along with EU heavyweights France and Germany, will be represented by their national security advisors.
The EU special representative for the South Caucasus, Estonian diplomat Toivo Klaar, will also attend.
The meeting comes a week after a lightning offensive by government forces established Azerbaijani control in Nagarno-Karabakh.
Armenian and Azerbaijan have fought a 30-year conflict over the breakaway region, mainly populated by ethnic Armenians.
Ethnic Albanian fighters have begun to disarm and thousands are fleeing the region.
The separatist government said in a statement on Tuesday that "13 unidentified bodies" had been found and seven more people died in hospital after a fuel depot explosion on Monday.
France's President Emmanuel Macron expressed his concern over the situation. "France is right now very vigilant concerning the territorial integrity of Armenia. Because that's what's at stake," he said in a televised interview on Sunday.
He added that Russia was now "complicit" with Baku while Azerbaijan's ally Turkey "has always been a supporter of its (Azerbaijan's) actions".
Armenia has publicly distanced itself from its traditional ally Russia, which has failed to show any concrete support for Yerevan in the current conflict.
Macron said that the Azerbaijan authorities were now "uninhibited" and "threatening the border of Armenia."
The ethnically Armenian region of Nagorno-Karabakh is internationally recognised as part of Azerbaijan, but has been run by a separatist administration for three decades.
Spectre of 1915 Armenian genocide looms over Nagorno-Karabakh
Azerbaijan already regained control of part of Karabakh in a 2020 war and now appears set on taking the rest of the territory.
Yerevan said on Sunday that Armenian Prime Minister Nikol Pashinyan and Azerbaijani President Ilham Aliyev will hold a pre-arranged meeting in Spain next month but Macron made no mention of this summit.
"We will provide political support so that a lasting peace that can be negotiated," said Macron.
Armenia on Tuesday said a total of 13,350 refugees had arrived from Nagorno-Karabakh from Azerbaijan.
UN meeting set as US, France seek to halt Karabakh fighting
Most of the refugees seen by French news agency AFP were women and children, including some from Eghtsahogh, where people took shelter around a Russian peacekeeping base after their village allegedly came under Azerbaijani shelling.
"Yesterday, we had to put down our rifles. So we left," a man in his thirties from the village of Mets Shen told AFP as a first group of a few dozen people crossed the border and registered with Armenian officials in Kornidzor.
Meanwhile, Turkish President Recep Tayyip Erdogan arrived in the Azerbaijani exclave of Nakhichevan on Monday for a one-day visit to meet his counterpart, Ilham Aliyev, according to the Hürryiet Daily News, a Turkish newspaper.
The meeting in the territory between Armenia and Iran on the border with Turkey was officially designed to launch the construction of a gas pipeline but the two presidents were also due to discuss Nagorno-Karabakh and the opening to Azerbaijanis of Armenia's Zangezur corridor, Turkish media reported.
Russia "welcomes" meeting
Erdogan's visit to close ally Azerbaijan comes as Armenia claims that its own security partner, Russia, did not offer enough support. Moscow "categorically" denied the claims.
Russia welcomed the meeting between Erdogan and Aliyev on Monday.
"We always hope that all meetings held by the president of Azerbaijan, including those with the Turkish president, will serve to normalize life in Nagorno-Karabakh after what happened," said Kremlin