According to a Senior Executive Intelligence Brief titled, ‘Terrorism: Bin Ladin Determined to Strike in the US’ on August 7, 2001: “The millennium plotting in Canada in [December] 1999 may have been part of Bin Ladin’s first serious attempt at a terrorist strike in the US. Convicted plotter Ahmed Ressam says that he conceived the idea to attack Los Angeles International Airport himself, but also that Bin Ladin lieutenant Abu Zubaydah encouraged him and helped facilitate the operation. Ressam also said that in 1998 Abu Zubaydah was planning his own US attack. Ressam says Bin Ladin was aware of the Los Angeles operation.”
– CIA, “Terrorism: Bin Ladin Determined to Strike in the US,” (Senior Executive Intelligence Brief), The Central Intelligence Agency’s 9/11 File:, The National Security Archive, Aug. 7, 2001