Last week's deadly attack in Brussels refocused America's attention on terrorism and elevated national security as a topic in the U.S. presidential contest.
Europe's second major terrorist attack in the last five months sparked heated rhetoric on America's presidential campaign trail. Republican Ted Cruz pledged to destroy Islamic State.
"And we will do that though overwhelming air power, through carpet-bombing them into oblivion," Cruz said at a rally in Wisconsin.
Meanwhile, Republican frontrunner Donald Trump said the United States is at risk.
"Terrorism is out of control," Trump said Sunday on ABC's This Week television program. "And if we're not very, very strong and very, very smart, we have a big, big problem coming up."
The Brussels attack did not cause President Barack Obama to alter his itinerary in Cuba and Argentina last week.
"We're going to root out and defeat ISIL," Obama said in his weekly address Saturday, adding that military might alone cannot root out terrorism and that America must lead by example.
"Our openness to refugees fleeing ISIL's violence. Our determination to win the battle against ISIL's hateful and violent propaganda – a distorted view of Islam that aims to radicalize young Muslims to their cause. In that effort, our most important partners are Muslim-Americans," the president said.
WATCH: Weekly presidential address
That message was echoed by Democratic presidential frontrunner Hillary Clinton.
"We cannot give in to panic and fear. It's not in keeping with our values, it's not effective in protecting us, and, and it plays into the hands of terrorists," Clinton said.
Republicans accuse Obama of weakness in the face of a growing terrorist threat.
"He [Obama] refuses to say the words ‘radical Islamic terrorism.' But instead he lectures us on Islamophobia. Well, enough is enough," Cruz said. "Here's what we're going to do with ISIS. We should use overwhelming force, kill the enemy, and then get the heck out."
Democratic presidential candidate Bernie Sanders says Muslim nations must lead the fight.
"I am opposed to the United States getting involved in perpetual warfare in the Middle East," Sanders said on This Week.
After last year's terrorist attacks in Paris, polls showed a spike in Americans' security concerns in an election cycle in which economic themes often have been predominant.