After Brussels Terror Attack, Obama Says No Need for a 'Plan B' Against ISIS

Obama Comments on Brussels Attacks, Isis and Policing Muslim Neighborhoods 4:49

BUENOS AIRES, Argentina — A day after terrorists launched a wave of bomb blasts in Belgium's capital, President Barack Obama was faced with questions Wednesday over whether the deadly attacks have made him rethink his strategy on crushing ISIS — and if he has a "plan B."

His answers emphasized what he sees as recent successes in the fight to dismantle the terror group, vowing that it would ultimately be destroyed.

But with scores dead and wounded in the heart of Europe's de facto capital, the president brushed aside critics who say his strategy against ISIS is too cautious against an enemy keen on slaughtering civilians.

Related: Obama to Cruz: Singling Out Muslims 'Makes No Sense'

"What I have been clear about is when it comes to defending the United States or its allies and our core interests, I will not hesitate to use military force where necessary," Obama said, deflecting criticism that he's been too reluctant to deploy U.S. troops on the battlefield.

"But how we do that is important. We don't just go ahead and blow something up just so that we can go back home and say we blew something up," said the president, who is making his first official state visit to Argentina.

He would not directly answer a question about whether more attacks are inevitable. But defeating ISIS, which has claimed responsibility for the coordinated carnage in Paris last November as well as in Brussels, is the most pressing issue, he said.

"It is the top priority of my national security team. It is the top priority of our military. It is the top priority of our intelligence officers. It is the top priority of our diplomats," he said. "But we are approaching this in a way that has a chance of working — and it will work."

The Obama administration's strategy to dismantle ISIS continues to be an extremely sensitive issue during America's increasingly contentious election cycle.

In recent weeks, the president and his administration have been trumpeting what they insist has been a turning point in the campaign against ISIS: Retaking 40 percent of the territory ISIS captured in Iraq and Syria; coordinating some 10,000 airstrikes, leaving the leadership "hunkered down"; and reducing the flow of foreign fighters transiting back and forth between Europe and ISIS-held territory.

Related: Paris Bomb-Maker Believed to Have Died in Brussels Attack

And Obama has been unsparing in his counterattacks on Republicans such as Donald Trump, who has controversially called for a wall to be built along the border with Mexico and the banning of Muslims from entering the United States.

While in Argentina, Obama also took a swipe at GOP presidential nominee Sen. Ted Cruz, who wants more aggressive patrolling and monitoring of Muslim neighborhoods in America.

"As far as the notion of having surveillance of neighborhoods where Muslims are present, I just left a country that engages in that kind of neighborhood surveillance, which, by the way, the father of Sen. Cruz escaped for America, the land of the free," Obama said, referring to Cuba, where he had traveled from following a historic trip.

"The notion that we would start down that slippery slope makes absolutely no sense," he added. "It's contrary to who we are."

Ted Cruz: We Must Destroy ISIS or Terror Attacks Will Continue 2:05

Administration officials, meanwhile, said there was no plan to change the president's itinerary and return to Washington, D.C., as the hunt for those responsible for the Brussels attacks intensifies. He plans to travel Thursday with the first lady and their daughters to the Patagonia region in the southern part of Argentina, a popular tourist destination known for its crystal clear lakes and panoramic mountains, for a day of leisure activities before returning home.

On Tuesday, Obama faced criticism for attending a baseball game in Cuba with President Raul Castro hours after the deadly terror attacks in Europe.

"It's very important for us not to respond with fear," Obama said, responding to the criticism.

He noted Boston's response to the marathon bombings in 2013, saying the people "taught us a lesson" by grieving and apprehending the bombers. In a few days, "folks went out shopping" and filled Fenway Park for a baseball game where attendees proudly sang the national anthem, Obama recalled.

The president insisted that remaining "resolute" and "steady" would ultimately end with obliterating ISIS.

"Groups like (ISIS) can't destroy us, they can't defeat us," he said. "They're not an existential threat to us."