New York, New Jersey and London have been rocked by the terrorist attack that killed at least eight people in France.
The US state department has said it is “deeply saddened” by the incident.
A second US-led coalition aircraft is helping France on the ground.
Here’s what you need to know.
Isis claimed responsibility for the attack, but there is no evidence of its involvement.
French authorities said the attacker drove his car into a crowd of people on a crowded Paris street before being shot dead by a policeman.
French President Emmanuel Macron said he was “shocked and saddened by the tragedy”.
He said the country had been “in a state of shock and mourning”.
“We have lost a hero,” he said.
The incident began around 10.30am local time when a man approached a security guard in a crowded street in the central Paris suburb of Bordeaux.
A woman, aged in her 30s, was shot in the leg.
The attacker was shot dead.
The French interior ministry has not yet released the identity of the attacker.
Mr Macron said the suspect “lived on the fringes of society” and had no criminal record.
“But we don, unfortunately, know the motivation.” “
What is Isis? “
But we don, unfortunately, know the motivation.”
What is Isis?
IS is a hardline Sunni Islamist group with a hard line agenda.
It controls swathes of territory in Iraq and Syria.
The group has also declared an Islamic caliphate across parts of Iraq and the Levant, including areas under its control in Syria.
IS fighters have been killing and kidnapping people in Iraq, Syria and other parts of the Middle West for years.
What is the US-France alliance?
US President Donald Trump said his country would be working with French and British counterparts to coordinate their response.
The two countries are working together on the fight against IS.
Mr Trump said: ”We have an obligation to fight for peace in the world, to fight terrorism and to fight the group that has declared an all-encompassing caliphate and is killing innocent people around the world.
“That is why I think it is absolutely imperative that we work together to bring this evil to its knees, and the United States of America will do everything possible to assist in this effort.”
He added that the US and France had “long-standing strategic relationships”, including “a close working relationship” with the US military.
What has the US said about the attack?
President Trump has called for the United Nations Security Council to investigate.
The White House said the US “strongly condemns” the attack and called for its immediate and unconditional withdrawal from the region.
The Trump administration also announced it would begin an economic boycott of countries that did not expel Mr Assad.
What’s the reaction in France?
President Emmanuel “Laurent” Macron has spoken of “a national unity and solidarity” in France, saying he would hold a national day of mourning on Monday.
He also said that France would honour the victims and their families in the days to come.
The president said: I am not a religious person, I am a human being, and we will honour them and their memory and their suffering.
“I do not know why these people are killing innocents and then killing us,” he added.
The country has been rocked for years by terrorist attacks.
In 2015, more than 300 people were killed in attacks across the country, and more than 500 were killed last year in the deadliest wave of violence since World War Two.
The Paris attack came just weeks after gunmen stormed a restaurant in the northern city of Nice and killed 84 people.