Responding to critics of President Obama's decision to attend a baseball game in Cuba shortly after Tuesday's terror attacks in Brussels, Secretary of State John Kerry borrowed the words of conservative writer Charles Krauthammer, declaring, "The president of the United States' schedule is not set by terrorists."

Mr. Obama was on the second full day of his historic visit to Cuba when ISIS-affiliated terrorists bombed several sites in Brussels, killing at least 31 people and injuring over 300. The president addressed the attacks shortly after they occurred, but he decided to maintain his prearranged plan to go to a baseball game with Cuban President Raul Castro. And on Wednesday, during a visit to Argentina, the president accepted an invitation to dance a tango during a state dinner.

Republicans criticized the moves, saying they did not reflect the seriousness of the events in Europe. "President Obama should be back in America keeping this country safe or President Obama should be planning to travel to Brussels," said Texas Sen. Ted Cruz, a GOP presidential candidate.

But the president countered, saying the "whole premise of terrorism is to try to disrupt people's ordinary lives."

"They cannot defeat America. They don't produce anything, they don't have a message that appeals to the vast majority of Muslims or the vast majority of people around the world," he said. "What they can do is scare and make people afraid and disrupt our daily lives and divide us. And as long as we don't allow that to happen, we're going to be OK."

Kerry echoed that line on Saturday, saying, "Life doesn't stop because one terrible incident takes place in one place."

"The President of the United States has major diplomatic responsibilities. He has to engage with other countries," Kerry said. "That was an important part of trying to build a relationship and achieve some of our goals with respect to human rights, with respect to transformation...in Cuba and elsewhere."

Even as the president stuck to his itinerary in Latin America, Kerry added, the administration stayed fully abreast of the situation in Europe.

"The president responded to it. He talked to the prime minister of Belgium from Cuba," he said. "I talked to the foreign minister from Cuba....an FBI team went to Belgium, is working with them now. We've been in direct contact every minute. So I don't think the president lost one tick...on the contrary, he continued what he had to do to engage in the diplomacy that had been pre-decided on."

For more of our interview with Secretary of State John Kerry, tune into "Face the Nation" tomorrow morning. Check your local listings for airtimes.