UAE President Sheikh Khalifa called on for the nation to unite in prayer following the death of Omani leader Sultan Qaboos bin Said.
Sheikh Khalifa ordered prayers to be carried out in all state mosques after Maghrib prayer on Saturday.
The president led tributes from across the Emirates and around the world to Sultan Qaboos, who died on Friday evening at the age of 79.
Sultan Qaboos ruled Oman for nearly half a century.
His death was announced by the official Oman News Agency.
Oman’s Defence Council has announced that Haitham bin Tariq Al Said will be his successor.
The written constitution required the ruling family to choose a successor within three days of the throne falling vacant.