According to the statement, which was broadcast on Omani state television, the decision was taken “based on the public interest”.
Sultan Qaboos also serves as Omani prime minister. Asaad al-Said, 63, is now Oman’s second deputy prime minister after Fahd bin Mahmoud al-Said, who serves as deputy premier for cabinet affairs.
Asaad al-Said has served as the sultan’s “special representative” since 2002 and is seen as a likely successor to 77-year-old Qaboos.
Since his return from a medical trip abroad in April of last year, the Sultan has rarely appeared in public.
Unlike his counterparts elsewhere in the the Gulf, Sultan Qaboos -- who has no children or siblings -- has not named a crown prince.