Saudi King Abdullah Bin AbdulAziz. (AP)
Saudi King Abdullah has left a New York hospital to convalesce, the royal court announced on Wednesday, one month after his departure for back surgery sparked speculation about the future of the kingdom's leadership.
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.
Saudi television showed Abdullah, about 86 years old, together with Health Minister Abdullah al-Rabeeah, walking with difficulty and smiling at hospital staff.
There was no mention of when the king would return to Saudi Arabia.
As head of a government led by several princes in their 70s and 80s, many also suffering chronic health problems, Abdullah's travelling to the United States for treatment sparked quiet speculation about the future of the leadership in many Saudi circles.
He 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. On December 4 he underwent surgery a second time to repair several vertebrae, a procedure that the court said had been planned by his doctors.
The second operation too was declared a success but until Wednesday no official news of his condition had been released.
US Vice President Joe Biden paid a visit to the hospital and met with Abdullah's family on December 15, the White House said, but apparently did not meet the king himself.
Abdullah's advanced age combined with his back hernia raised concerns about the future of the world's biggest oil exporter, which has been ruled by the Al-Saud family since 1932.
The crown prince, Abdullah's half brother Prince Sultan bin Abdul Aziz, who has been defence minister since 1962, is also in his mid-80s and has been slowed by what is believed to be cancer.
Little seen for the past two years, Sultan returned from Morocco on November 21 to assume control of the royal government in Abdullah's absence.
Prince Nayef bin Abdul Aziz, presumed second-in-line for the throne and interior minister for the past 35 years, is much more active but at 76 is believed to have his own health challenges.
The other top royals, including Prince Saud al-Faisal, foreign minister since 1975, and the Riyadh governor for 48 years, Prince Salman bin Abdul Aziz, 71, have also all spent substantial time abroad in the past year being treated for chronic ailments.
Any hint at possible change in the absolute monarchy, founded in 1932, is keenly watched as the OPEC kingpin pumps about 8.2 million barrels of crude per day.
Abdullah is credited with advancing much-needed reforms in the ultra-conservative Islamic state since he became king in 2005, and maintaining the country as a staunch ally of the United States.