Attorney General John Ashcroft said at a news conference that intelligence reports and public statements by people associated with Al Qaeda suggested that the terrorist group was "almost ready to attack the United States" and harbored a "specific intention to hit the United States hard."
http://www.nytimes.com/2004/05/27/politics/27terror.html

The administration did not raise the terrorist threat advisory from its current level of elevated, or yellow, and the White House said Mr. Bush would not alter his schedule because of security concerns.

Asked about the timing of his new warnings about the suspects, Mr. Ashcroft said, "We believe the public, like all of us, needs a reminder."

Some intelligence officials said they were uncertain that the link between the fresh intelligence and the likelihood of another attack was as apparent as Mr. Ashcroft made it out to be. Officials at the Department of Homeland Security said just a day before Mr. Ashcroft's announcement that they had no new intelligence pointing to the threat of an attack.