Ben Carson called for more U.S. intervention abroad, promoting the use of "covert resources, overt resources, military resources... in an attempt not to contain them but to eliminate them before they eliminate us."
"I think America's involvement should be trying to eliminate them, completely, destroy them," Carson said at a Friday press conference. "Boots on the ground would probably be important."
Jeb Bush said he was "not surprised" about the terrorist attacks.
In a radio interview with conservative talk show host Hugh Hewitt, Bush said, "This is a war being created by Islamic terrorists. It's not a law enforcement operation. And the mindset that, in our country, at least, needs to change to recognize it for what it is. This is an organized effort to destroy Western civilization."
The former Florida governor also called for America to lead in the counterterrorism fight -- what he called "the war of our time" -- pushing to "re-garner the alliances, fortify those alliances, reconnect with our counterintelligence and intelligence capabilities with our European allies, and engage in the Middle East to take out ISIS."
Another Florida Republican, Sen. Marco Rubio, called for more assistance to the French government in tracking down those responsible for the attacks.
"As we learn more about the attacks and who is behind them, the United States should assist the French government in finding those who are accountable and bringing them to justice," Rubio said in a statement. "We cannot let those who seek to disrupt our way of life succeed. We must increase our efforts at home and abroad to improve our defenses, destroy terrorist networks, and deprive them of the space from which to operate."
Ohio Gov. John Kasich led an impromptu prayer for the Paris victims during a campaign stop in New Hampshire.
"Dear Lord, we keep the families in Paris in our prayers, the children who've been frightened to learn of the death of their mom or their dad or their brother or their sister," he said Friday. "We know this evil can be all around us, but we know in the end it's the strength that you provide, the hope ultimately that you provide, that can help these folks deal with this terrible tragedy and recover. And we'll stand with them, Lord, here across the ocean and the United States. We'll do the best to hold them in our arms, to be with them in this time of terrible grief and terrible tragedy."
The next day, speaking at the Sunshine Summit, Kasich called for timely action in the wake of the attacks in France.
"You know, our thoughts and our prayers go to the people of France but that's not enough. Action is required. Time is of the essence. Negotiation, ambivalence, or delay, are not acceptable," he said in a speech that focused entirely on the terror attacks.
Later, he told reporters that when it comes to the "way we should treat Syrian refugees, it ought to be an affirmation where we are clear we're not bringing ISIS into this country."