"The Secretary General is extremely concerned about the renewed resumption of hostilities along the line of contact in the Nagorno-Karabakh conflict zone ... urges the parties to immediately cease hostilities, reduce tensions and immediately return to constructive negotiations," the commentary said.
Guterres also announced his intention to hold talks with Azerbaijani President Ilham Aliyev and Armenian Prime Minister Nikol Pashinyan.
Earlier, French President Emmanuel Macron called for taking all measures to end the violence and de-escalate the situation in Nagorno-Karabakh.
Russian President Vladimir Putin also expressed concern over the resumption of large-scale clashes in Nagorno-Karabakh.