(CNN) U.S. President Barack Obama toughened his rhetoric against ISIS at a weekend press conference in Malaysia that concluded his nine-day trip abroad.

The group responsible for the Paris terror attacks is "a bunch of killers with good social media ," he said. "They are dangerous and they've caused great hardship to ... an overwhelming majority of people."

Children stand next to a burnt vehicle during clashes between Iraqi security forces and ISIS militants in Mosul on Tuesday, June 10.

Children stand next to a burnt vehicle during clashes between Iraqi security forces and ISIS militants in Mosul on Tuesday, June 10.

A Syrian rebel fighter lies on a stretcher at a makeshift hospital in Douma, Syria, on Wednesday, July 9. He was reportedly injured while fighting ISIS militants.

A Syrian rebel fighter lies on a stretcher at a makeshift hospital in Douma, Syria, on Wednesday, July 9. He was reportedly injured while fighting ISIS militants.

A Baiji oil refinery burns after an alleged ISIS attack in northern Selahaddin, Iraq, on Thursday, July 31.

A Baiji oil refinery burns after an alleged ISIS attack in northern Selahaddin, Iraq, on Thursday, July 31.

Thousands of Yazidi and Christian people flee Mosul on Wednesday, August 6, after the latest wave of ISIS advances.

Thousands of Yazidi and Christian people flee Mosul on Wednesday, August 6, after the latest wave of ISIS advances.

Thousands of Yazidis are escorted to safety by Kurdish Peshmerga forces and a People's Protection Unit in Mosul on Saturday, August 9.

Thousands of Yazidis are escorted to safety by Kurdish Peshmerga forces and a People's Protection Unit in Mosul on Saturday, August 9.

Aziza Hamid, a 15-year-old Iraqi girl, cries for her father while she and some other Yazidi people are flown to safety Monday, August 11, after a dramatic rescue operation at Iraq's Mount Sinjar. A CNN crew was on the flight, which took diapers, milk, water and food to the site where as many as 70,000 people were trapped by ISIS. But only a few of them were able to fly back on the helicopter with the Iraqi Air Force and Kurdish Peshmerga fighters.

Aziza Hamid, a 15-year-old Iraqi girl, cries for her father while she and some other Yazidi people are flown to safety Monday, August 11, after a dramatic rescue operation at Iraq's Mount Sinjar. A CNN crew was on the flight, which took diapers, milk, water and food to the site where as many as 70,000 people were trapped by ISIS. But only a few of them were able to fly back on the helicopter with the Iraqi Air Force and Kurdish Peshmerga fighters.

Displaced Iraqis receive clothes from a charity at a refugee camp near Feeshkhabour, Iraq, on Tuesday, August 19.

Displaced Iraqis receive clothes from a charity at a refugee camp near Feeshkhabour, Iraq, on Tuesday, August 19.

Kurdish Peshmerga fighters fire at ISIS militant positions from their position on the top of Mount Zardak, east of Mosul, Iraq, on Tuesday, September 9.

Kurdish Peshmerga fighters fire at ISIS militant positions from their position on the top of Mount Zardak, east of Mosul, Iraq, on Tuesday, September 9.

A elderly man is carried after crossing the Syria-Turkey border near Suruc on Saturday, September 20.

A elderly man is carried after crossing the Syria-Turkey border near Suruc on Saturday, September 20.

Syrian Kurds wait near a border crossing in Suruc as they wait to return to their homes in Kobani on Sunday, September 28.

Syrian Kurds wait near a border crossing in Suruc as they wait to return to their homes in Kobani on Sunday, September 28.

A Kurdish Peshmerga soldier who was wounded in a battle with ISIS is wheeled to the Zakho Emergency Hospital in Duhuk, Iraq, on Tuesday, September 30.

A Kurdish Peshmerga soldier who was wounded in a battle with ISIS is wheeled to the Zakho Emergency Hospital in Duhuk, Iraq, on Tuesday, September 30.

Alleged ISIS militants stand next to an ISIS flag atop a hill in Kobani on Monday, October 6.

Alleged ISIS militants stand next to an ISIS flag atop a hill in Kobani on Monday, October 6.

Kiymet Ergun, a Syrian Kurd, celebrates in Mursitpinar, Turkey, after an airstrike by the U.S.-led coalition in Kobani on Monday, October 13.

Kiymet Ergun, a Syrian Kurd, celebrates in Mursitpinar, Turkey, after an airstrike by the U.S.-led coalition in Kobani on Monday, October 13.

Cundi Minaz, a female Kurdish fighter, is buried in a cemetery in the southeastern Turkish town of Suruc on Tuesday, October 14. Minaz was reportedly killed during clashes with ISIS militants in nearby Kobani.

Cundi Minaz, a female Kurdish fighter, is buried in a cemetery in the southeastern Turkish town of Suruc on Tuesday, October 14. Minaz was reportedly killed during clashes with ISIS militants in nearby Kobani.

Heavy smoke rises in Kobani following an airstrike by the U.S.-led coalition on October 18.

Heavy smoke rises in Kobani following an airstrike by the U.S.-led coalition on October 18.

Kurdish fighters walk to positions as they combat ISIS forces in Kobani on Sunday, October 19.

Kurdish fighters walk to positions as they combat ISIS forces in Kobani on Sunday, October 19.

ISIS militants stand near the site of an airstrike near the Turkey-Syria border on Thursday, October 23. The United States and several Arab nations have been bombing ISIS targets in Syria to take out the militant group's ability to command, train and resupply its fighters.

ISIS militants stand near the site of an airstrike near the Turkey-Syria border on Thursday, October 23. The United States and several Arab nations have been bombing ISIS targets in Syria to take out the militant group's ability to command, train and resupply its fighters.

Iraqi special forces search a house in Jurf al-Sakhar, Iraq, on Thursday, October 30, after retaking the area from ISIS.

Iraqi special forces search a house in Jurf al-Sakhar, Iraq, on Thursday, October 30, after retaking the area from ISIS.

A picture taken from Turkey shows smoke rising after ISIS militants fired mortar shells toward an area controlled by Syrian Kurdish fighters near Kobani on Monday, November 3.

A picture taken from Turkey shows smoke rising after ISIS militants fired mortar shells toward an area controlled by Syrian Kurdish fighters near Kobani on Monday, November 3.

Fighters from the Free Syrian Army and the Kurdish People's Protection Units join forces to fight ISIS in Kobani on Wednesday, November 19.

Fighters from the Free Syrian Army and the Kurdish People's Protection Units join forces to fight ISIS in Kobani on Wednesday, November 19.

Smoke billows behind an ISIS sign during an Iraqi military operation to regain control of the town of Sadiyah, about 95 kilometers (60 miles) north of Baghdad, on Tuesday, November 25.

Smoke billows behind an ISIS sign during an Iraqi military operation to regain control of the town of Sadiyah, about 95 kilometers (60 miles) north of Baghdad, on Tuesday, November 25.

An elderly Yazidi man arrives in Kirkuk after being released by ISIS on Saturday, January 17. The militant group released about 200 Yazidis who were held captive for five months in Iraq. Almost all of the freed prisoners were in poor health and bore signs of abuse and neglect, Kurdish officials said.

An elderly Yazidi man arrives in Kirkuk after being released by ISIS on Saturday, January 17. The militant group released about 200 Yazidis who were held captive for five months in Iraq. Almost all of the freed prisoners were in poor health and bore signs of abuse and neglect, Kurdish officials said.

ISIS militants are seen through a rifle's scope during clashes with Peshmerga fighters in Mosul, Iraq, on Wednesday, January 21.

ISIS militants are seen through a rifle's scope during clashes with Peshmerga fighters in Mosul, Iraq, on Wednesday, January 21.

Junko Ishido, mother of Japanese journalist Kenji Goto, reacts during a news conference in Tokyo on Friday, January 23. ISIS would later kill Goto and another Japanese hostage, Haruna Yukawa.

Junko Ishido, mother of Japanese journalist Kenji Goto, reacts during a news conference in Tokyo on Friday, January 23. ISIS would later kill Goto and another Japanese hostage, Haruna Yukawa.

Collapsed buildings are seen in Kobani on January 27 after Kurdish forces took control of the town from ISIS.

Collapsed buildings are seen in Kobani on January 27 after Kurdish forces took control of the town from ISIS.

Kurdish people celebrate in Suruc, Turkey, near the Turkish-Syrian border, after ISIS militants were expelled from Kobani on Tuesday, January 27.

Kurdish people celebrate in Suruc, Turkey, near the Turkish-Syrian border, after ISIS militants were expelled from Kobani on Tuesday, January 27.

A Kurdish marksman looks over a destroyed area of Kobani on Friday, January 30, after the city had been liberated from the ISIS militant group. The Syrian city, also known as Ayn al-Arab, had been under assault by ISIS since mid-September.

A Kurdish marksman looks over a destroyed area of Kobani on Friday, January 30, after the city had been liberated from the ISIS militant group. The Syrian city, also known as Ayn al-Arab, had been under assault by ISIS since mid-September.

Safi al-Kasasbeh, right, receives condolences from tribal leaders at his home village near Karak, Jordan, on Wednesday, February 4. Al-Kasasbeh's son, Jordanian pilot Moath al-Kasasbeh, was burned alive in a video that was recently released by ISIS militants. Jordan is one of a handful of Middle Eastern nations taking part in the U.S.-led military coalition against ISIS.

Displaced Assyrian women who fled their homes due to ISIS attacks pray at a church on the outskirts of Damascus, Syria, on Sunday, March 1. ISIS militants abducted at least 220 Assyrians in Syria.

Displaced Assyrian women who fled their homes due to ISIS attacks pray at a church on the outskirts of Damascus, Syria, on Sunday, March 1. ISIS militants abducted at least 220 Assyrians in Syria.

Iraqi Shiite fighters cover their ears as a rocket is launched during a clash with ISIS militants in the town of Al-Alam, Iraq, on Monday, March 9.

Iraqi Shiite fighters cover their ears as a rocket is launched during a clash with ISIS militants in the town of Al-Alam, Iraq, on Monday, March 9.

The parents of 19-year-old Mohammed Musallam react at the family's home in the East Jerusalem Jewish settlement of Neve Yaakov on Tuesday, March 10. ISIS released a video purportedly showing a young boy executing Musallam, an Israeli citizen of Palestinian descent who ISIS claimed infiltrated the group in Syria to spy for the Jewish state. Musallam's family told CNN that he had no ties with the Mossad, Israel's spy agency, and had, in fact, been recruited by ISIS.

On April 1, Shiite militiamen celebrate the retaking of Tikrit, which had been under ISIS control since June. The push into Tikrit came days after U.S.-led airstrikes targeted ISIS bases around the city.

On April 1, Shiite militiamen celebrate the retaking of Tikrit, which had been under ISIS control since June. The push into Tikrit came days after U.S.-led airstrikes targeted ISIS bases around the city.

People in Tikrit inspect what used to be a palace of former President Saddam Hussein on April 3.

People in Tikrit inspect what used to be a palace of former President Saddam Hussein on April 3.

A Yazidi woman mourns for the death of her husband and children by ISIS after being released south of Kirkuk on April 8. ISIS is known for killing dozens of people at a time and carrying out public executions, crucifixions and other acts.

A Yazidi woman mourns for the death of her husband and children by ISIS after being released south of Kirkuk on April 8. ISIS is known for killing dozens of people at a time and carrying out public executions, crucifixions and other acts.

Kurdish Peshmerga forces help Yazidis as they arrive at a medical center in Altun Kupri, Iraq, on April 8.

Kurdish Peshmerga forces help Yazidis as they arrive at a medical center in Altun Kupri, Iraq, on April 8.

Yazidis embrace after being released by ISIS south of Kirkuk, Iraq, on Wednesday, April 8. ISIS released more than 200 Yazidis , a minority group whose members were killed, captured and displaced when the Islamist terror organization overtook their towns in northern Iraq last summer, officials said.

Thousands of Iraqis cross a bridge over the Euphrates River to Baghdad as they flee Ramadi on Friday, April 17.

Thousands of Iraqis cross a bridge over the Euphrates River to Baghdad as they flee Ramadi on Friday, April 17.

A member of Afghanistan's security forces stands at the site where a suicide bomber on a motorbike blew himself up in front of the Kabul Bank in Jalalabad, Afghanistan, on Saturday, April 18. ISIS claimed responsibility for the attack. The explosion killed at least 33 people and injured more than 100 others, a public health spokesman said.

A member of Afghanistan's security forces stands at the site where a suicide bomber on a motorbike blew himself up in front of the Kabul Bank in Jalalabad, Afghanistan, on Saturday, April 18. ISIS claimed responsibility for the attack. The explosion killed at least 33 people and injured more than 100 others, a public health spokesman said.

Iraqi soldiers fire their weapons toward ISIS group positions in the Garma district, west of the Iraqi capital of Baghdad, on Sunday, April 26. Pro-government forces said they had recently made advances on areas held by Islamist jihadists.

Iraqi soldiers fire their weapons toward ISIS group positions in the Garma district, west of the Iraqi capital of Baghdad, on Sunday, April 26. Pro-government forces said they had recently made advances on areas held by Islamist jihadists.

People search through debris after an explosion at a Shiite mosque in Qatif, Saudi Arabia, on Friday, May 22. ISIS claimed responsibility for the attack, according to tweets from ISIS supporters, which included a formal statement from ISIS detailing the operation.

Residents examine a damaged mosque after an Iraqi Air Force bombing in the ISIS-seized city of Falluja, Iraq, on Sunday, May 31. At least six were killed and nine others wounded during the bombing.

Residents examine a damaged mosque after an Iraqi Air Force bombing in the ISIS-seized city of Falluja, Iraq, on Sunday, May 31. At least six were killed and nine others wounded during the bombing.

Syrians wait near the Turkish border during clashes between ISIS and Kurdish armed groups in Kobani, Syria, on Thursday, June 25. The photo was taken in Sanliurfa, Turkey. ISIS militants disguised as Kurdish security forces infiltrated Kobani on Thursday and killed "many civilians," said a spokesman for the Kurds in Kobani.

Syrians wait near the Turkish border during clashes between ISIS and Kurdish armed groups in Kobani, Syria, on Thursday, June 25. The photo was taken in Sanliurfa, Turkey. ISIS militants disguised as Kurdish security forces infiltrated Kobani on Thursday and killed "many civilians," said a spokesman for the Kurds in Kobani.

People in Ashmoun, Egypt, carry the coffin for 1st Lt. Mohammed Ashraf, who was killed when the ISIS militant group attacked Egyptian military checkpoints on Wednesday, July 1. At least 17 soldiers were reportedly killed, and 30 were injured.

Protesters in Istanbul carry anti-ISIS banners and flags to show support for victims of the Suruc suicide blast during a demonstration on Monday, July 20.

Protesters in Istanbul carry anti-ISIS banners and flags to show support for victims of the Suruc suicide blast during a demonstration on Monday, July 20.

Mourners in Gaziantep, Turkey, grieve over a coffin Tuesday, July 21, during a funeral ceremony for the victims of a suspected ISIS suicide bomb attack. That bombing killed at least 31 people in Suruc, a Turkish town that borders Syria. Turkish authorities blamed ISIS for the attack.

Saudi officials and investigators check the inside of the mosque on August 6.

Saudi officials and investigators check the inside of the mosque on August 6.

The governor of the Asir region in Saudi Arabia, Prince Faisal bin Khaled bin Abdulaziz, left, visits a man who was wounded in a suicide bombing attack on a mosque in Abha, Saudi Arabia, on August 6. ISIS claimed responsibility for the explosion, which killed at least 13 people and injured nine others.

Buildings reduced to piles of debris can be seen in the eastern suburbs of Ramadi on August 6.

Buildings reduced to piles of debris can be seen in the eastern suburbs of Ramadi on August 6.

Smoke rises as Iraqi security forces bomb ISIS positions in the eastern suburbs of Ramadi, Iraq, on August 6.

Smoke rises as Iraqi security forces bomb ISIS positions in the eastern suburbs of Ramadi, Iraq, on August 6.

An ISIS fighter poses with spoils purportedly taken after capturing the Syrian town of al-Qaryatayn.

An ISIS fighter poses with spoils purportedly taken after capturing the Syrian town of al-Qaryatayn.

In this image taken from social media, an ISIS fighter holds the group's flag after the militant group overran the Syrian town of al-Qaryatayn on Thursday, August 6, the London-based Syrian Observatory for Human Rights reported. ISIS uses modern tools such as social media to promote reactionary politics and religious fundamentalism. Fighters are destroying holy sites and valuable antiquities even as their leaders propagate a return to the early days of Islam.

Iraqi men look at damage following a bomb explosion that targeted a vegetable market in Baghdad on Thursday, August 13. ISIS claimed responsibility for the attack.

Iraqi men look at damage following a bomb explosion that targeted a vegetable market in Baghdad on Thursday, August 13. ISIS claimed responsibility for the attack.

Smoke rises above a damaged building in Ramadi, Iraq, following a coalition airstrike against ISIS positions on Saturday, August 15.

Smoke rises above a damaged building in Ramadi, Iraq, following a coalition airstrike against ISIS positions on Saturday, August 15.

Shiite fighters, fighting alongside Iraqi government forces, fire a rocket at ISIS militants as they advance toward the center of Baiji, Iraq, on Monday, October 19.

Shiite fighters, fighting alongside Iraqi government forces, fire a rocket at ISIS militants as they advance toward the center of Baiji, Iraq, on Monday, October 19.

An explosion rocks Kobani, Syria, during a reported car bomb attack by ISIS militants on Tuesday, October 20.

An explosion rocks Kobani, Syria, during a reported car bomb attack by ISIS militants on Tuesday, October 20.

Members of the Egyptian military approach the wreckage of a Russian passenger plane Sunday, November 1, in Hassana, Egypt. The plane crashed the day before, killing all 224 people on board. ISIS claimed responsibility for downing the plane, but the group's claim wasn't immediately verified.

Syrian government troops walk inside the Kweiras air base on Wednesday, November 11, after they broke a siege imposed by ISIS militants.

Syrian government troops walk inside the Kweiras air base on Wednesday, November 11, after they broke a siege imposed by ISIS militants.

Smoke rises over the northern Iraqi town of Sinjar on November 12. Kurdish Iraqi fighters, backed by a U.S.-led air campaign, retook the strategic town, which ISIS militants overran last year. ISIS wants to create an Islamic state across Sunni areas of Iraq and Syria.

Emergency personnel and civilians gather at the site of a twin suicide bombing in Beirut, Lebanon, on Thursday, November 12. The bombings killed at least 43 people and wounded more than 200 more. ISIS appeared to claim responsibility in a statement posted on social media.

Wounded people are helped outside the Bataclan concert hall in Paris following a series of coordinated attacks in the city on Friday, November 13. The militant group ISIS claimed responsibility for the attacks, which killed at least 130 people and wounded hundreds more.

Investigators check the scene of a mosque attack Friday, November 27, in northern Bangladesh's Bogra district. ISIS has claimed responsibility for the attack that left at least one person dead and three more wounded.

Yemenis check the scene of a car bomb attack Sunday, December 6, in Aden, Yemen. Aden Gov. Jaafar Saad and six bodyguards died in the attack , for which the terror group ISIS claimed responsibility.

Syrian pro-government forces gather at the site of a deadly triple bombing Sunday, January 31, in the Damascus suburb of Sayeda Zeynab . ISIS claimed responsibility for the attack, according to a statement circulating online from supporters of the terrorist group.

Syrians gather at the site of a double car bomb attack in the Al-Zahraa neighborhood of the Homs, Syria, on February 21, 2016. Multiple attacks in Homs and southern Damascus kill at least 122 and injure scores, according to the state-run SANA news agency. ISIS claimed responsibility.

Wounded passengers are treated following a suicide bombing at the Brussels Airport on March 22, 2016. The attacks on the airport and a subway killed 32 people and wounded more than 300. ISIS claims its "fighters" launched the attacks in the Belgian capital.

The global coalition formed to destroy ISIS "will not relent," he vowed. "We will not accept the idea that terrorist assaults on restaurants and theaters and hotels are the new normal, or that we are powerless to stop them."

Obama's stronger language on ISIS came after days of criticism for his response to the tragedy in Paris but did not signal a policy shift by the administration.

"They can't beat us on the battlefield, so they try to terrorize us into being afraid, and changing our patterns of behavior, and panicking, and abandoning our allies and partners, and retreating from the world," Obama said. "As president, I will not let that happen."

It's "absolutely false" that "we are somehow at war with an entire religion," he said. "The United States could never be at any war with any religion because America is made up by multiple religions. We're strengthened by people from every religion, including Muslim Americans. So I want to be as clear as I can on this -- prejudice and discrimination helps (ISIS) and undermines our national security."

Obama was hit with a wave of criticism in the wake of the terrorists' attacks in France and Lebanon, which left hundreds dead. At a press conference a few days after 130 people were slaughtered in France's capital, Obama described that burst of violence as a "setback" in the battle against ISIS.

Photos: Night of terror: Paris attacks Photos: Night of terror: Paris attacks A forensic scientist works near a Paris cafe on Saturday, November 14, following a series of coordinated attacks in Paris the night before that killed scores of people. ISIS has claimed responsibility. Hide Caption 1 of 32 Photos: Night of terror: Paris attacks Police are out in force November 14 near La Belle Equipe, one of the sites of the terror attacks. Hide Caption 2 of 32 Photos: Night of terror: Paris attacks Forensic police search for evidence inside the Comptoir Voltaire cafe after the attacks. Hide Caption 3 of 32 Photos: Night of terror: Paris attacks Shoes and a bloody shirt lie outside the Bataclan concert hall on November 14. Most of the fatalities occurred at the Bataclan in central Paris. Hide Caption 4 of 32 Photos: Night of terror: Paris attacks Security forces evacuate people on Rue Oberkampf near the Bataclan concert hall early on November 14. Hide Caption 5 of 32 Photos: Night of terror: Paris attacks Medics evacuate an injured woman on Boulevard des Filles du Calvaire near the Bataclan early on November 14. Hide Caption 6 of 32 Photos: Night of terror: Paris attacks Police, firefighters and rescue workers secure the area near the Bataclan concert hall on November 14. Hide Caption 7 of 32 Photos: Night of terror: Paris attacks A man with blood on his shirt talks on the phone on November 14. He is next to the Bataclan theater, where gunmen shot concertgoers and held hostages until police raided the building. Hide Caption 8 of 32 Photos: Night of terror: Paris attacks Police officers patrol the area around Notre Dame cathedral in Paris on November 14. Hide Caption 9 of 32 Photos: Night of terror: Paris attacks Police officers patrol Paris' Saint-German neighborhood on November 14. Hide Caption 10 of 32 Photos: Night of terror: Paris attacks Victims of the shooting at the Bataclan concert venue in central Paris are evacuated to receive medical treatment on November 14. Hide Caption 11 of 32 Photos: Night of terror: Paris attacks A woman is evacuated from the Bataclan theater early on November 14. Hide Caption 12 of 32 Photos: Night of terror: Paris attacks Forensics are working in the street of Paris after the terrorist attack on Friday, November 13. The words "horror," "massacre" and "war" peppered the front pages of the country's newspapers, conveying the shell-shocked mood. Hide Caption 13 of 32 Photos: Night of terror: Paris attacks Rescuers evacuate an injured person near the Stade de France, one of several sites of attacks November 13 in Paris. Thousands of fans were watching a soccer match between France and Germany when the attacks occurred. Hide Caption 14 of 32 Photos: Night of terror: Paris attacks A survivor of the terrorist attack in the Bataclan is assisted following terror attacks, November 13. The violence at the Bataclan, which involved a hostage-taking, resulted in the highest number of casualties of all the attacks. Hide Caption 15 of 32 Photos: Night of terror: Paris attacks Spectators invade the pitch of the Stade de France stadium after the international friendly soccer match between France and Germany in Saint-Denis. Hide Caption 16 of 32 Photos: Night of terror: Paris attacks Spectators embrace each other as they stand on the playing field of the Stade de France stadium at the end of a soccer match between France and Germany in Saint-Denis, outside Paris, on November 13. Hide Caption 17 of 32 Photos: Night of terror: Paris attacks A body, covered by a sheet, is seen on the sidewalk outside the Bataclan theater. Hide Caption 18 of 32 Photos: Night of terror: Paris attacks Rescuers evacuate an injured person on Boulevard des Filles du Calvaire, close to the Bataclan concert hall in central Paris. Hide Caption 19 of 32 Photos: Night of terror: Paris attacks Wounded people are evacuated outside the scene of a hostage situation at the Bataclan theater in Paris on November 13. Hide Caption 20 of 32 Photos: Night of terror: Paris attacks A medic tends to a wounded man following the attacks near the Boulevard des Filles du Calvaire. Hide Caption 21 of 32 Photos: Night of terror: Paris attacks A woman walks past police and firefighters in the Oberkampf area of Paris. Hide Caption 22 of 32 Photos: Night of terror: Paris attacks A riot police officer stands by an ambulance near the Bataclan concert hall in central Paris. Hide Caption 23 of 32 Photos: Night of terror: Paris attacks Wounded people are evacuated outside the Bataclan concert hall. Hide Caption 24 of 32 Photos: Night of terror: Paris attacks Police secure the Stade de France in Saint-Denis, north of Paris, following explosions during the soccer match between France and Germany. Hide Caption 25 of 32 Photos: Night of terror: Paris attacks A wounded man is evacuated from the Stade de France in Saint-Denis, outside Paris. Hide Caption 26 of 32 Photos: Night of terror: Paris attacks Spectators gather on the field of the Stade de France after the attacks. Explosions were heard during the soccer match between France and Germany. Hide Caption 27 of 32 Photos: Night of terror: Paris attacks French security forces rush in as people are evacuated in the area of Rue Bichat in the 10th District of Paris. Hide Caption 28 of 32 Photos: Night of terror: Paris attacks People leave the Stade de France after explosions were heard near the stadium during a soccer match between France and Germany on Friday. Paris Deputy Mayor Patrick Klugman told CNN President Francois Hollande was at the match and was evacuated at halftime. Hide Caption 29 of 32 Photos: Night of terror: Paris attacks Victims lay on the pavement outside a Paris restaurant. Hide Caption 30 of 32 Photos: Night of terror: Paris attacks Rescue workers and medics tend to victims at the scene of one of the shootings, a restaurant in the 10th District. Attackers reportedly used AK-47 automatic weapons in separate attacks across Paris, and there were explosions at the Stade de France. Hide Caption 31 of 32 Photos: Night of terror: Paris attacks French security forces move people in the area of Rue Bichat in the 10th District. A witness told BFMTV that firefighters were on the scene to treat the injured. Hide Caption 32 of 32

The Obama administration had said it wanted the U.S. to accept at least 10,000 Syrian refugees in the next year.

On Thursday, the House swiftly passed a bill that would suspend the program allowing Syrian and Iraqi refugees into the country until key national security agencies certify they don't pose a security risk

"People have understandably been so concerned, given how similar Paris is to many American cities, that I get why legislation in the House moved forward quickly," Obama said Sunday. "My hope though is, now that we have some time to catch our breath and take a look at this carefully, that people understand that refugees who end up in the United States are the most vetted, scrutinized, thoroughly investigated individuals that ever arrived on American shores."

The process that has been "constructed over the course of several administrations, on a bipartisan basis, is extraordinarily thorough," he said.

It already takes between 18 and 24 months for someone to be approved, he noted.

The legislation that passed only "gums up the works so much" that "effectively, you don't see any refugees being admitted."