Saudi Crown Prince Sultan bin Abdul-Aziz will visit the United States soon for medical tests, state media said.

Prince Sultan, who is also the defence minister of the world's top oil exporter, will leave the kingdom on Saturday for a "private holiday", and medical tests in the United States, state media said in a brief report.

Prince Sultan, who is about 86, had returned home in November from Morocco where he had spent about three months following unspecified medical treatment in the United States.

Western diplomats had said the prince was coming home then to avoid a power vacuum after it was announced that King Abdullah would go to the United States for medical treatment. - Reuters