Saudi Arabia's King Abdullah has named the country's interior minister as the new crown prince.

Nayef bin Abdel-Aziz al-Saud was named heir in a royal decree read out on state television Thursday.

He succeeds prince Sultan bin Abdulaziz al Saud who died in New York on Saturday after undergoing treatment for an undisclosed illness.

Prince Nayef will assume the Saudi throne upon the death of 87-year-old King Abdullah.

The 78-year-old prince has led the interior ministry since 1975 and is closely aligned with the country's conservative clerics.