WASHINGTON (AFP) - The director of the Federal Bureau of Investigation (FBI) saidon Thursday (Nov 19)there was no specific threat to the United States of a Paris-style terror attack and played down video warnings by the Islamic State in Iraq and Syria (ISIS).
Major Western world cities are on high alert after the extremists said they were responsible for Friday's wave of gun and bomb attacks on the French capital that killed at least 129 people.
A new ISIS propaganda video has emerged threatening New York, in which a man prepares a suicide vest and is seen fingering its trigger, interlaced with footage of Times and Herald Squares.
But FBI Director James Comey said: "We are not aware of any credible threat here (in the US) of a Paris-type attack. And we have seen no connection at all between the Paris attackers and the United States.
"ISIL and its supporters put out all kinds of propaganda like videos and magazines, but that is not credible intelligence," he said, using an alternative acronym for ISIS.
"Of course we investigate all of those propaganda threats. But instead the threat here focuses primarily on troubled souls in America who are being inspired or enabled online to do something violent for ISIL."
Underlining the scale of the task the authorities face attempting to avert a repeat of the 9/11 attacks, US Attorney-General Loretta Lynch said the Justice Department was working "around the clock" to keep the United States safe.
"Since 2013 we have charged more than 70 individuals for conduct related to foreign fighter interest and home grown violent extremism," said Ms Lynch, speaking alongside Mr Comey in Washington, as they attempted to put a nervous public at ease.
"And we continue to take robust actions to monitor and to thwart potential extremist activity."
Those efforts include working with Washington's allies, said Ms Lynch, after the attacks on Paris signaled a dangerous, new phase in the struggle against radical Islam.
"They want us to live in fear, and we refuse," said Ms Lynch.
"They want us to change who we are and what makes us quintessentially American, and that we will never do."
Ms Comey said that the US authorities had successfully tracked down individuals who wished harm on America, particularly in the lead-up to July 4 Independence Day, and that the Paris attacks had focused anew the drive to keep the US safe.
"We will keep watching them and if we see something, we'll work to disrupt it," he said of any would-be attackers.
And he had a message for the people of the United States: "The most important thing I think is do not let fear become disabling. That is what the terrorists want. They want you to imagine them in the shadows. They want you to imagine them as something greater than they are.
"Instead, we hope that you will turn fear into healthy awareness of what's around you. If you see something that gives you a bad feeling, tell somebody in law enforcement."