Gaddafi has called the alleged plot "a fabricated case, an intentionally destructive thing." In an interview published last month in Time magazine, he said: "We have a good relationship with Saudi Arabia. My personal relationship with Prince Abdullah is a good one."
The State Department has listed Libya as a state sponsor of terrorism since 1979 and stiffened international economic sanctions in 1988, when Libyan agents planted a bomb that blew up Pan Am Flight 103 over Lockerbie, Scotland, killing 270 people. The United Nations removed international sanctions against Libya in September 2003 after Gaddafi publicly renounced terrorism and agreed to compensate families of the Pan Am 103 victims.
Col. Moammar Gaddafi.
(Yousef Al Ajeli -- AP)
Libya also agreed last year to abandon its nuclear, chemical and biological weapons programs after holding secret negotiations with British and U.S. officials. Since then, the United States has eased restrictions on travel and conducting business in Libya, although the terrorism sanctions remain in place and the two countries do not have full diplomatic relations.
U.S. officials have been cautious in their public statements about the plot, saying they take the allegations seriously while continuing to pursue closer relations with the long-isolated North African state.
Last month, for instance, the State Department announced that it was lifting travel restrictions on Libyan diplomats posted at the United Nations in New York and at the liaison office in Washington. State Department spokesman Richard Boucher told reporters at the time that the decision was prompted by "our improved bilateral relationship" with Libya.
State Department officials said William J. Burns, assistant secretary of state for Middle East affairs, had met with Libyan government leaders seven times in the past year in Tripoli, Rome and London. On each occasion, they said, Burns raised concerns about Libyan involvement in the plot, and has repeatedly questioned the credibility of Libya's denials.
"We've reinforced our concerns about the allegations in all the high-level meetings that we've had with the Libyans; been doing that since the beginning," Boucher said.
In contrast, Saudi Arabia has moved to downgrade relations with Libya as its investigation has progressed.
On Dec. 22, Saudi Arabia announced the expulsion of Libya's ambassador and said it would withdraw its ambassador from Tripoli. Prince Saud Faisal, the Saudi foreign minister, said the move was prompted by the "ugliness" surrounding the assassination charges but added that the kingdom had decided not to sever relations completely.
Some U.S. officials have expressed skepticism about the seriousness of the plot, which the Saudi investigative documents describe as an amateurish plan concocted by Libyan agents that faltered on several occasions but nevertheless advanced to its final stages before it was broken up.
For example, the Libyan conspirators repeatedly ran into trouble when they tried to smuggle more than $1 million into the kingdom to pay off the Saudis hired to kill the crown prince, the documents show. At first, the Libyans transferred the money to the wrong bank in Medina. Then they attracted the notice of Saudi bank regulators when they withdrew large sums of cash from another branch in Mecca.
With the money finally in hand, the Libyan agents stuffed it into several bags and left them inside a room at the Hilton hotel in Mecca for pickup by a Saudi courier, the investigative documents show. But the courier panicked when he saw the piles of cash and fled empty-handed.
By the time Libyan agents found someone else to come get the money, Saudi security forces had gotten wind of the plot and arrested several suspects during the next attempted handover.
The star defendant at the trial in Riyadh is expected to be Col. Mohammed Ismail, a Libyan whom Saudi authorities accuse of orchestrating the plot. Ismail was arrested in Egypt on Nov. 27, 2003, hours after he left Saudi Arabia as the assassination plan fell apart. Saudi officials said he had confessed to his role and has also been interrogated by FBI and CIA agents.