Riyadh:  Saudi King Abdullah, 86, is to undergo more surgery on his back in the United States Friday, the royal court said.

"King Abdullah will return for surgery to repair several vertebrae in his spine in a follow-up to his previous treatment.... in accordance with the plan set by his medical team," the court said in a statement carried by the official SPA news agency.

King Abdullah flew to New York City on November 22 and was operated on two days later at New York Presbyterian Hospital for a debilitating herniated disc complicated by a haematoma that put pressure on his spine.
 

The operation ended successfully after a blood clot was removed, a slipped disc was adjusted and a vertebra was stabilised, the royal court then said in a statement carried by the state news agency.