A day after bombs ripped through Brussels, President Barack Obama declared Wednesday that fighting the Islamic State is his “No. 1 priority” and blasted Republican calls for surveillance of Muslim neighborhoods as counterproductive and contrary to U.S. values.

Obama took on presidential candidate Ted Cruz directly, comparing his proposal for a crackdown on Muslims to the restrictions on religion and free speech in communist Cuba, the nation Cruz’s father fled and Obama visited Tuesday.

“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. “The notion that we would start down that slippery slope makes absolutely no sense. It’s contrary to who we are.”

Obama showed no signs of altering his policies in the battle against the Islamic State group, which has claimed credit for the Brussels bombings. He described calls for more aggressive action as ill-conceived and said Republican talk of carpet bombing in Iraq and Syria is “inhumane.”

“That would likely be an extraordinary mechanism for ISIL to recruit more people willing to die and explode bombs in an airport or in a metro station. That’s not a smart strategy,” Obama said, using an alternative name for the Islamic State group.

The president spoke at a news conference in Buenos Aires, where he flew from Havana to meet with Argentina’s new president, Mauricio Macri. Obama’s historic trip, the first for a sitting president to Cuba in 90 years, was jarred but not interrupted by the bombings that killed at least 34 people and left some 270 injured. The president didn’t change his schedule, attending a baseball game Tuesday and continuing on to the second leg of this trip.

Obama argued that shifting his plans would show weakness to the terrorists, and he sought to show he was unfazed by the campaign-season blitz of criticism at home. He vowed to stick to the strategy in Iraq and Syria.

“I’ve got a lot of things on my plate, but my top priority is to defeat ISIL and to eliminate the scourge of this barbaric terrorism that’s been taking place around the world,” Obama said. “There’s no more important item on my agenda than going after them and defeating them. The issue is how do we do it in an intelligent way?”

As Obama traveled, Republican candidates put forward their own alternatives. Cruz said Tuesday that law enforcement should be empowered to “patrol and secure Muslim neighborhoods before they become radicalized.”

He also echoed similar statements from GOP front-runner Donald Trump, calling for an end to the flow of refugees from countries where the Islamic State militant group has a significant presence.

Obama said the strategy of a U.S.-led air campaign and special operations missions was evolving, but only in response to results on the ground, not GOP rhetoric.

“We are approaching this in a way that has a chance of working. And it will work,” he said. “And we’re not going to do things that are counterproductive simply because it’s political season. We’re going to be steady. We’re going to be resolute, and ultimately we’re going to be successful.”

(AP)