King Abdullah left the hospital on Tuesday evening "for his New York residence for a period of convalescence and physiotherapy," the court said in a statement carried by the official SPA news agency.

There was no mention of when Abdullah, about 86 years old, would return to Saudi Arabia.

The king flew to New York 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.

That operation was declared a success. But on December 4 he underwent surgery a second time to repair several vertebrae, a procedure that the court said had been planned.

The second operation too was declared a success but until Wednesday no official news of his condition had been released.