A US presidential envoy personally warned Saudi Arabia last week of fears of an imminent attack days before suicide bombings that killed 34 people, including seven Americans.
The disclosure was made after the United States, in a rare criticism, said Saudi Arabia "must deal with the fact that it has terrorists inside its own country" in the aftermath of the bombings.
US officials said Mr George W. Bush's deputy national security adviser, Mr Stephen Hadley, went to Riyadh last week to deliver the warning.
His visit came after the US State Department issued a May 1st warning for Americans to put off non-essential travel to Saudi Arabia because "information indicates that terrorist groups may be in the final phases of planning attacks against US interests in Saudi Arabia."
The US ambassador to Saudi Arabia, Mr Robert Jordan, complained yesterday that the Saudi kingdom did not respond quickly enough to US requests for more security at a compound attacked this week by the bombers.
"I obviously would have preferred a quicker response to ourrequests for additional security at these compounds," he said.
However, Saudi Foreign Minister Saud al-Faisal said his country was doing all it could to prevent terrorism.
The United States has strong suspicions that al-Qaeda was behind the bombings. An FBI team was on its way to Saudi Arabia to help investigate the triple suicide bombings.