European Council President Charles Michel is in touch with the leaders of Armenia and Azerbaijan.

"I am in contact with both leaders Ilham Aliyev and Nikol Pashinyan. Josep Borrell has asked EU Special Representative Klaar to travel to Baku and Yerevan to work on preventing further escalation," he tweeted.

"Reports about fighting on the #Armenia - #Azerbaijan border are extremely worrying.  Need a complete and sustainable ceasefire. There is no alternative to peace and stability - and there is no alternative to diplomacy to ensure that," he added.