Terming Mumbai terror attacks as "successful" from the perspective of terrorists, America's top intelligence official has warned that such strikes could be replicated in the US and other parts of the world.

Warning such attacks could be viewed by terrorists as a possible way of proceeding in the future, FBI Director Robert Muller said intelligence and other security agencies would have to reinvigorate efforts to make certain that we've done everything we can to prevent such type of attacks.

Delivering a speech on 'Global Terrorism: The FBI's Role', Muller said the Mumbai attack, which killed more than 170 people and wounded over 300 was an attack both highly coordinated and deceptively simple in its execution.

Muller, who took over the FBI just days before September 11, 2001, said the Mumbai attack had displayed the "terrorists with large agendas and little money can use rudimentary weapons to maximize their impact."

"It again raises the question of whether a similar attack could happen in Seattle, San Diego, Miami or Manhattan," he said.

Muller said although Al-Qaida remains a threat to the US and worldwide, security planners "must also focus on less well known terrorists groups as well as home grown terrorists".