Hollande told an exceptional meeting of both houses of parliament he would meet US President Barack Obama and Russia's Vladimir Putin in the coming days and called for a UN Security Council meeting over the fight against IS jihadists.
A grave Hollande said the attacks in the French capital that killed 129 people as they enjoyed a Friday night out in bars, restaurants, a concert hall and the national stadium, "were acts of war".
In response, France would "intensify" operations in Syria, Hollande said a day after French jets pounded IS targets in the group's Syrian stronghold of Raqa, its first military response to the Paris carnage.
"We will continue the strikes in the weeks to come," Hollande told lawmakers.
In the fight against the extremists, Hollande said he wanted increased international assistance.
"I will meet in the coming days with US President Obama and President Putin," he said.
Turning to measures within France, he said he would ask parliament to consider extending a state of emergency by three months.
