'Liberte, egalite, fraternite': Obama says US stands with France

"Those who think that they can terrorize the people of France or the values that they stand for are wrong," Obama said in a hastily convened appearance before reporters at the White House.

Obama was briefed on the series of attacks, which have killed at least 120 people, by his counterterrorism advisor Lisa Monaco.

"We are reminded in this time of tragedy that the bonds of liberte, egalite, fraternite, are not just the values French people share, but we share," he said citing France's national motto.

"Those go far beyond any act of terrorism or the hateful vision of those who perpetrated the crimes this evening."

The Department of Homeland Security reported there was "no specific or credible threat to the United States" in the wake of the attacks.

But authorities in New York were on a heightened state of alert. Counterterrorism police reinforcements deployed to crowded public places as a precautionary measure.

Units were also deployed to the French mission to the United Nations and the French Consulate.

The New York Police Department said detectives in its intelligence division "are conducting liaison activities to assist the Paris police in any way possible, while keeping the NYPD updated on the on-going situation."

Earlier Friday Obama had spoken to French President Francois Hollande by telephone to discuss his planned visit to Paris this month for climate change talks.

Obama said he had not immediately contacted Hollande again, because the French president was busy responding to the crisis.

But Obama pledged to work with France to bring those responsible to justice.

"Whenever these kinds of attacks happen, we've always been able to count on the French people to stand with us. They have been an extraordinary counterterrorism partner. And we intend to be there with them in that same fashion," Obama said.

"We stand prepared and ready to provide whatever assistance the government and people of France need to respond."

"It's an attack not just on the people of France. But this is an attack on all of humanity and the universal values we share."

Obama also expressed his resolve in tackling terror.

"We're going to do whatever it takes to work with the French people and with nations around the world to bring these terrorists to justice and to go after any terrorist networks that go after our people."

Vice President Joe Biden echoed that sentiment, saying "such savagery can never threaten who we are. We will respond. We will overcome. We will endure."

Secretary of State John Kerry said the US Embassy in Paris was "making every effort to account for the welfare of American citizens in the city."