Saudi Arabia is due to hold a funeral for the late Crown Prince Sultan bin Abdul-Aziz, who died of an undisclosed illness Saturday in New York.

U.S. Vice President Joe Biden is among the dignitaries expected to attend Tuesday's funeral in the Saudi capital, Riyadh.

Crown Prince Sultan was the heir to the Saudi throne and the half-brother of King Abdullah. He was one of the country's most powerful figures, serving also as the defense minister and deputy prime minister.

His body arrived back in Riyadh Monday from New York, where he had gone for treatment of recurring medical problems.

Saudi officials have not announced a successor, but Interior Minister Prince Nayaf is expected to be named the heir.

Prince Nayaf is said to have closer ties to Saudi Arabia's powerful, puritanical clerics than the king, who has instituted reforms, including allowing women to take part in future elections.

A special council will decide on the succession in a change of policy that was made by the current king. Crown Prince Sultan's son Khaled is expected to take over his father's duties at the defense ministry.

King Abdullah, Prince Nayaf and the late crown prince are all the sons of the founder of the modern Arab nation, Abdul-Aziz, known as Ibn Saud.