"Medvedev expressed a serious concern about the escalation of the situation around Nagorno-Karabakh. The Russian prime minister stressed the need to ensure the strict implementation of the ceasefire regime as well as the importance of a resumption of the process of political settlement," the press service said in a statement.
According to the document, Medvedev confirmed his planned official visit to Armenia on April 7-8.
The violence in Nagorno-Karabakh, a breakaway region of Azerbaijan with a predominantly Armenian population, escalated on Friday night. Baku and Yerevan have accused each other of provoking hostilities.
Following three days of heavy fighting, the conflicting sides agreed a ceasefire in the disputed region that came into force at noon on Tuesday.