Excerpts From Interview With Egyptian President
We knew that something was going to happen against the U.S., and we informed the U.S.

We informed the United States about that [warning] but we didn't know that such a thing could take place. We thought it was an embassy, an airplane, something, the usual thing, but to realize they were going to take airplanes and destroy [buildings], that is unbelievable. We didn't realize that what happened on Sept. 11 could happen in this way at all. Nobody would ever think of that, not even in the U.S. . . . But we knew that something was going to happen. We have good contact with the intelligence continuously, and I think there was some activity in which some element would bring the information and we started to use them, to tell them, "can you stop this, or delay this now, the time is not suitable," trying to give ourselves time to realize what may take place. I think this man, this agent, phoned the group of bin Laden, I don't remember who it was. He told them, "No, no, no, it's difficult to stop it." It was one week before. Because the wheels were going on, we couldn't stop it. One week or four days, a very short time. The wheels going on. All the information has been given to them [the United States]. That is why you were making tight security on the embassy. Even if you were intelligent, you couldn't imagine they were going to do such a thing.

Something is going to happen in the U.S. . . . to the United States, maybe inside the U.S., maybe in airplane, maybe in embassies. We couldn't know. We tried to know where, but this information we didn't reach.
http://www.nytimes.com/2002/06/04/national/04MTEX.html