At the same time, ISIS threatened the United States that it could be next.
"I swear to God, as we struck France in its stronghold Paris, we will strike America in its stronghold, Washington," an ISIS fighter declared in a video released Monday.
The speech, and ISIS' latest threat, came as police scoured France and Belgium in a hunt for suspects in Friday's brutal attacks, which left at least 129 dead and 352 wounded.
Hollande calls for new laws
In a rare speech to a joint session of parliament, Hollande urged lawmakers to approve a three-month extension of the nation's state of emergency, new laws that would allow authorities to strip the citizenship from French-born terrorists and provisions making it easier to deport suspected terrorists.
He also proposed adding 5,000 positions to the country's national paramilitary police force and said he would not propose cuts in the nation's defense spending until at least 2019.
He said France would intensify its attacks on ISIS and called for a U.N. Security Council meeting to discuss the worldwide threat posed by the group.
"We are not committed to a war of civilizations, because these assassins don't represent any civilization," Hollande said. "We are in a war against terrorism, jihadism, which threatens the whole world."
"Terrorism will not destroy France, because France will destroy it," Hollande said.
Raids across France
French police carried out raids around the country overnight into Monday, bringing to 150 the number of raids under the country's state of emergency since Friday.
A rocket launcher and bulletproof vest were among the items authorities seized, French Interior Minister Bernard Cazeneuve said. The interior minister said he had ordered that 104 people be put under house arrest since the attacks.
In Belgium, authorities arrested seven people in weekend raids. Five of them have been released, according to Jean-Pascal Thoreau of Belgium's federal prosecutor's office.
As details emerge about the seven terrorists killed in the attacks
, an international manhunt is underway for Salah Abdeslam, who has already managed to slip through the fingers of authorities at least once.
Suspect at large described as dangerous
Abdeslam is a 26-year-old French citizen who was born in Belgium, French police said in a public request for information
, warning that he is dangerous and should not be approached. Belgium has issued an international warrant for his arrest.
Hours after the attacks, he was driving in the direction of the Belgian border when police stopped and questioned him, a source close to the investigation into the Paris attacks said.
The French newspaper Le Monde reported that police hadn't yet linked him to the Paris attacks when they stopped him and two other people in a black Volkswagen Golf. When Belgian police stopped the car later Saturday, Abdeslam was no longer in it. Now, his whereabouts are unknown.
Investigators haven't said much about how they believe Abdeslam is tied to the shootings and bombings that targeted people at restaurants, bars, a concert venue and a sports stadium.
One of his brothers was a suspect killed in the attacks, Thoreau said. Another brother was arrested by Belgian police but later released.
The French newspaper Le Monde reported that Abdeslam rented the black Volkswagen Polo that was found outside the Bataclan concert hall where three attackers massacred at least 89 people
before blowing themselves up or being shot by police.
Car found with weapons inside
Le Monde reported that Salah Abdeslam's older brother, Ibrahim, was the suicide bomber whose explosives detonated at a cafe on boulevard Voltaire in eastern Paris during the wave of attacks on the city. The Paris prosecutor's office has identified that attacker as a 31-year-old French citizen but hasn't disclosed his name.
According to Le Monde, Ibrahim Abdeslam rented the black Seat car that authorities say was used in the string of deadly attacks on restaurants and bars on Friday. But it's not yet clear whether he was in the vehicle at the time of the attacks, the newspaper said.
The Seat was found abandoned in the eastern Paris suburb of Montreuil with three Kalashnikov automatic rifles inside, CNN affiliate BFMTV reported Sunday.
Another brother, Mohammed Abdeslam, spoke to CNN affiliate BFMTV after his release from custody, saying his parents were in shock.
"My family and I are affected by what happened. We found out by TV just like many of you," he said. "We did not think for a moment that one of our brothers was related to these attacks."
French officials believe that six of the people directly involved in the attacks had spent time in Syria, BFMTV reported Monday.
Two prominent ISIS members, Abdelhamid Abaaoud and Salim Benghalem, may have been involved in planning or masterminding the Paris attacks, a source close to the ongoing investigation tells CNN. Both have been involved in multiple terrorist plots in recent years and are believed to be in Syria or Iraq.
Syrian passport holder linked to refugee flow
Attention is also heavily focused on a Syrian passport found near the body of one of the three Stade de France bombers. The passport and a registration document for refugee status issued by Greek authorities led officials to a troubling conclusion, according to a French senator: The bomber was among a group of Syrian refugees who arrived on the Greek island of Leros on October 3.
The senator, who was briefed by France's interior minister, told CNN
that the man was carrying the passport and also a registration document for refugee status by Greek authorities. The fingerprints of the passport holder taken by Greek authorities match those of the terrorist who blew himself up at the Stade de France, the senator said.
The Paris prosecutor's office on Monday confirmed the link, saying the passport bearing the name of Ahmad Al Mohammad, a 25-year-old from Idlib, still needs to be verified.
The possible tie between one of the Paris attackers and the refugees from the Syrian war flocking to Europe this year has intensified concerns about how to handle the influx of people.
European politicians who've been speaking out against the rush of migrants are already pointing to the attacks as another reason to close their countries' borders. And governors in at least 24 U.S. states have said they won't accept Syrian refugees
in light of the Paris attacks.
Attack raises concerns internationally
In Britain, authorities said they would increase security for Tuesday's soccer match between England and France. And in Washington, transit police stepped up patrols
to safeguard the city's mass transit system.
More patrols, more dogs and random explosives screenings were introduced, along with unseen countermeasures meant to prevent an attack, the Metro Transit Police Department said.
The Department of Homeland Safety said it had no "specific credible information of an attack on the U.S. homeland."
CIA Director John Brennan said he would be surprised if the group doesn't have additional attacks in preparation.
"I would anticipate this is not the only operation they have in the pipeline," he said. "I do believe this is something we will have to deal with for quite some time."
City on edge
On Monday, Parisians tried to return to school and work in a city scarred by its second major terror attack this year. In January, terrorists stormed the offices of the satirical newspaper Charlie Hebdo
, killing 12.
At one intersection, police who arrived to direct traffic Monday were met by worried pedestrians asking "Is anything happening?"
At a Paris school, a father said, "It's difficult to let them go off to school and for us to return to work, for everyone. We're all just going to have to look out for one another."
Patrick Klugman, the city's deputy mayor, told CNN the evidence police have found in raids reveals a pattern.
"In every attack we had so far in the past, we find a lot of heavy war material not used. So we know that it's easy to find weapons in France, in Belgium, to commit attacks. And we know that they have the capacity to cause major damage," he said. "They did on Friday and probably they can again. That's why intelligence is so important."