President Obama: Overcoming Fear 'Most Powerful Tool' to Fight ISIS The president spoke with reporters closing out his nine-day trip overseas.

KUALA LUMPUR, Malaysia -- The “most powerful tool” to fight ISIS is to prevent the group's recent terror attacks in Paris from injecting fear in communities or governments around the world, President Obama said Sunday during his trip to Malaysia.

“We do not succumb to fear,” Obama said during a news conference closing out the final leg of his nine-day, three-nation trip overseas. “The most powerful tool we have to fight ISIL is to say that we’re not afraid. To not elevate them and to somehow buy into their fantasy that they’re doing something important.”

Speaking on the sidelines of the East Asia Summit in Kuala Lumpur, the president sought to reassure allies that the U.S. will continue as an effective leader of the global coalition to destroy ISIS.

“Destroying ISIL is not only a realistic goal,” Obama said, using a preferred acronym for the terror group. “We’re going to get it done and we’re going to pursue it. It’s going to get done.”

Obama, who is set to visit Paris at the end of the month for a major climate conference, said world leaders would be sending an important message by not letting last week's attack in Paris, in which 130 people were killed, prevent them from attending.

“I think it is absolutely vital for every country, every leader to send a signal that the viciousness of a handful of killers does not stop the world from doing vital business,” he said.

The president also decried news headlines that sought to label the recently-deceased ringleader of the Paris attacks, Abdelhamid Abaaoud, as a “mastermind.”

“He’s not a mastermind,” Obama said. “He found a few other vicious people, got [his] hands on some fairly conventional weapons, and sadly, it turns out if you’re willing to die, you can kill a lot of people.”

The president added that ISIS "cannot strike a mortal blow" to the U.S., France, or even Malaysia.

"They’re a bunch of killers with good social media," he said. "Our way of life is stronger. We have more to offer. We represent 99.9 percent of humanity and that's why we should be confident that we will win."

Obama also gave his first public acknowledgment of ISIS being behind the downing of a Russian airliner over Egypt late last month, killing more than 200 people. An image included in the latest issues of an ISIS magazine shows a soda can and what explosives experts told ABC News earlier this week are a blasting cap and an electric initiator.

The ISIS magazine said the image showed “the IED [improvised explosive device] used to bring down the Russian airliner.”

"I do think that as a consequence of ISIL claiming responsibility for bringing down their plane, there is an increasing awareness on the part of [Russian] President [Vladimir] Putin that ISIL poses a greater threat to them than anything else in the region," said the president.

National Security Advisor Susan Rice said after the press conference that the U.S. agrees ISIS took down the plane.