President Barack Obama called Saudi King Abdullah, who is in a US hospital undergoing treatment for a herniated disc, to wish him well, the White House said Tuesday.
Obama called "to convey his best wishes for a full and quick recovery from medical treatment that the King is receiving in the United States," the White House said in a brief statement.
"Both leaders reaffirmed the importance of the US-Saudi bilateral relationship," the statement read.
A spokesman for the Saudi Health Minister said the king was suffering from a "lumbar spine disc prolapse complicated with a haematoma pressing on lower nerve roots causing pain" - a painful but treatable ailment.
Before traveling to the United States, Abdullah, 86, tasked his half-brother Crown Prince Sultan bin Abdul Aziz - officially 79 but believed to be aged closer to 85 - with running the country in his absence.
A close US ally, Saudi Arabia is the richest and one of the most influential countries in the Middle East, holding some 20 per cent of the world's proven oil reserves.