Saudi King Abdullah underwent successful back surgery at a hospital here, according to a statement from the Saudi Arabian royal court.
The 86-year-old king traveled to the United States earlier this week for treatment in New York's Presbyterian Hospital after suffering from a slipped disc and being diagnosed with a blood clot pressing on the nerves in his back.
The king had "a back surgery, in which the blood clot was extracted, the slipped disc was corrected, and the injured vertebrae was stabilised." the Saudi Press Agency quoted a Royal statement as saying.
"The operation was accomplished successfully," it said.
King Abdullah had named Crown Prince Sultan to administer the oil-rich state's affairs in the monarch's absence, the state-run Saudi Press Agency reported.
"The medical team recommended that he leaves for the US to visit a spine-specialised medical center in order to complete medical examinations and for follow-up treatment," health minister Abdullah al-Rabeeah had said.
Doctors performed tests on the monarch last Friday after he complained of back pain, and he underwent more tests on Sunday, the Saudi Press Agency reported.
The top three figures in the kingdom — Abdullah, Sultan and Prince Nayef, the country's interior minister and second deputy Prime Minister — are all sons of King Abdul Aziz Ibn Saud, who founded modern Saudi Arabia in 1932.
Mr Abdullah has ruled the oil-rich kingdom since the August 2005 death of his half-brother, King Fahd. But Mr Abdullah ran most of the kingdom's affairs for a decade before that on behalf of his ailing half-brother.