EU foreign policy chief Josep Borrell expressed deep anxiety over reports about ongoing military activities in the breakaway region. Armenia and Azerbaijan have accused each other of extending the fighting.
The European Union's diplomatic chief on Sunday expressed his deep concern over reports of violations of a cease-fire between neighbors Armenia and Azerbaijan in the disputed Nagorno-Karabakh region.
"We note with extreme concern the reports of continued military activities, including against civilian targets, as well as civilian casualties," Borrell said in a statement.
He added that the bloc's 27 member states should "engage in substantive negotiations without delay" under the auspices of the so-called Minsk Group, a decadeslong process led by France, Russia and the United States to find a lasting solution to the conflict.
The statement came after a cease-fire on Saturday was swiftly broken by Armenia, which carried out attacks targeting civilian areas in Ganja, which left nine dead.
Borrell welcomed the cease-fire and called on all sides to "strictly abide" by it.
Fighting in the region broke out on Sept. 27, when Armenian forces targeted civilian Azerbaijani settlements and military positions, leading to casualties.
Relations between the two former Soviet republics have been tense since 1991 when the Armenian military occupied Nagorno-Karabakh, an internationally recognized territory of Azerbaijan.