U.S. President Barack Obama says a “lone wolf” terrorist, such as the gunman who killed 77 people in Norway last month, is a bigger concern than a large-scale terror attack.

President Obama said in an interview with CNN television Tuesday that it is a lot harder to trace a single deranged terrorist driven by hateful ideology.

The president said the risk is always there for a large, well-coordinated terrorist attack. He said that authorities are on heightened awareness with the 10th anniversary of the September 11th attacks approaching.

But Mr. Obama says extraordinary progress made in degrading al-Qaida's capabilities has made it a much weaker organization than it was just a few years ago.