PARIS - At least 77 people have died in the alleged terrorist attack on Bastille day by a truck driver in Nice, the mayor of Nice Christian Estrosi reported.

French president Francois Hollande and prime minister Manuel Valls are now in the inter-ministerial crisis cell due to the attack.

A spokeswoman for the Elysee Palace told Efe that Hollande went to the crisis cell in the Ministry of Interior where Valls was to receive further information from Nice.

The president earlier canceled his trip to Avignon in the south of the country to return hastily to Paris where he chairs the crisis cell.

From 09.00 local time (0700 GMT), Hollande will preside over a security and defense council meeting with ministers and the main authorities in these matters, said the spokeswoman for the Elysee.

Hollande had indicated this afternoon, hours before the Nice attack, that the state of emergency declared immediately after the terrorist attacks in Paris on Nov. 13, 2015 would be lifted on Jul. 26.

Meanwhile, US president Barack Obama said in a statement that "we have offered any assistance that they may need to investigate this attack and bring those responsible to justice."

"We stand in solidarity and partnership with France, our oldest ally, as they respond to and recover from this attack," Obama added.

The US president also showed his admiration for "the extraordinary resilience and democratic values that have made France an inspiration to the entire world" and he is convinced that this character will "endure long after this devastating and tragic loss of life."