King Abdullah was back in Saudi Arabia on Saturday after flying home early from a convalescence stay in Morocco to follow events, as the Syrian conflict intensified, state media reported.
The king flew back last evening (Friday) from Morocco, where he had been staying since May 31, "because of the turn of events that the region is currently going through," the official SPA news agency said.
The news agency did not elaborate but the king's return came hours after Washington announced that it would provide weapons to the Syrian rebels for the first time because of what it described as reliable intelligence that the Damascus regime had made small-scale use of chemical weapons.
Saudi Arabia is a key supporter of the Syrian rebels and has long advocated providing them with better weaponry.
The 89-year-old monarch still has difficulty walking despite two operations to repair what doctors have described as "a ligamentary slackening in the upper back."
The king's age and frequent hospitalisations have raised concerns about the future leadership of the world's key oil producer.