"Let me also reiterate that the EU supports the territorial integrity, independence and sovereignty of Azerbaijan,” European Council President Donald Tusk said in Baku. "The EU and its member states have not recognized Nagorno-Karabakh.”

Tusk said the status quo in the conflict is unsustainable and the peaceful resolution of the Nagorno-Karabakh conflict remains a priority for the EU. 

"We continue to support the mediation efforts of the OSCE Minsk Group co-chairs,” he said.

Armenia captured nearly 20 percent of Azerbaijan’s internationally recognized territory, including Nagorno-Karabakh and seven adjacent districts, in a war in the early 1990s.

While major hostilities ended with a ceasefire in 1994, no peace agreement has been signed.

Armenians have yet to comply with four UN Security Council resolutions passed in 1993 calling for immediate and unconditional withdrawal from the occupied Azerbaijani territory.