President Bush signs a new immigration bill aimed at making it more difficult for terror suspects to enter the country. Recommendations include increased border checks and closer monitoring of foreign students. All passports issued after 2003 must now contain fingerprints or facial recognition technology.

Vice-President Dick Cheney says it is "almost certain" al-Qaeda will carry out another terror attack on America.

The FBI plans to shift nearly 500 agents from other criminal investigations to counter terrorism. Nearly a quarter of the FBI 11,500 agents will be working on terrorism. The bureau is also making a massive effort to improve intelligence gathering by hiring hundreds of linguists, computer experts and scientists.

FBI director Robert Mueller acknowledges that investigators might have been able to uncover part of the plot that led to the terror attacks of 11 September. This is believed to be the first time a US official has admitted this. Mr Mueller said if all the clues had been put together, "who is to say" what could have been discovered.

FBI guidelines give agents more latitude to monitor e-mails, internet sites, libraries and religious institutions without first having evidence of criminal activity. A spokesperson for the American Civil Liberties Union says: "The FBI is telling the American people that they no longer have to do anything unlawful to get that knock on the door."