Armenian President Armen Sarkissian has been admitted to hospital to be treated for Covid-19 complications, his office was quoted as saying by Russian news agencies on Friday.
The Russian news agency Interfax had earlier cited local media reports saying Sarkissian, 67, was undergoing treatment for heart problems.
"Some complications have appeared in connection with the coronavirus infection sustained by the president of Armenia," Russian news agencies quoted his office as saying. "He is undergoing tests."
Sarkissian declined on Thursday to sign a decree on the appointment of a new head of the army's general staff after Prime Minister Nikol Pashinyan sacked the previous chief during a political crisis in which the army urged Pashinyan to resign.