BRUSSELS -- The thoughts and prayers of the American people are with Belgium after the attacks in Brussels, and the United States stands in solidarity with Belgium in condemning the attacks, U.S. President Barack Obama said Tuesday during a speech in Havana, Cuba.
"We can and we will" defeat terrorists, he said. "This is yet another reminder that the world must unite," he added. "We must be together, regardless of" nationality or faith or race, in fighting terrorism, he said.
President Barack Obama was briefed on the attacks in Brussels and interrupted his trip to Cuba to talk about the situation.
Connecticut's federal leaders also reacted Tuesday to this latest round of violence.
"It's heartbreaking to see our friends and allies in Brussels go through the kind of terror we've seen," said Congresswoman Elizabeth Esty during an interview with FOX 61 from a studio in Washington D.C.
"I am horrified and saddened my heart goes out to the families,” said Senator Richard Blumenthal in Hartford.
ISIS has claimed responsibility for these latest attacks, heightening concerns around the terror group's coordination, sophistication, and planning.
"There needs to be much more effective sharing of intelligence and resources among European nations and among our nation,” said Blumenthal.
Blumenthal says we are at war with ISIS. He believes America's efforts against the group need to be bolstered, but he's not in favor of committing a large group of American military members on the ground. "We can provide air superiority, intelligence intercept, cut off of funding, other specific effective measures,” said Blumenthal.
Protecting the homeland is another major concern. Congresswoman Esty says we all need to stay vigilante.
"The real issue is we're seeing this self-radicalization, and that means we've got to be really smart on counter terrorism in the United States,” said Esty. “We need to work closely with state and local officials."
Esty's advice for Americans who may hesitate now to visit Europe?
"The terrorists win when we give in to fear and we allow chaos to reign,” said Esty, "I would hope people would continue to feel comfortable going to Europe, but keeping your wits about you anywhere you are."
Meanwhile, New York Gov. Andrew Cuomo has directed state law enforcement officials to "step up security at high-profile locations around the state, including our airports, bridges, tunnels and mass transit systems."
"Public safety is paramount, and I want the people of this state to know that we are working with all local and federal partners, remaining vigilant and taking all necessary measures to keep New Yorkers safe," he said in a statement.
New York Police Department spokesman J. Peter Donald said despite the increased efforts "at this time, there is no known indication that the attack has any nexus to New York City."
"The department has deployed additional counterterrorism resources across the city including: the Counterterrorism Response Command, the Strategic Response Group and Hercules Teams," he said. "These teams have been deployed to crowded areas and transit locations around the city out of an abundance of caution to provide police presence and public reassurance as we closely follow the developing situation overseas."
The stepped up security also applies to the Long Island Rail Road transit system at Penn Station, Metro North at Grand Central Station and other major hubs like the Atlantic Terminal in Brooklyn, according to a Metropolitan Transit Authority senior law enforcement official.
As for the presidential contenders, they too spoke out after the attacks.
Republican front-runner Donald Trump tweeted Tuesday that the U.S. must be vigilant and smart following the explosion.
"Do you all remember how beautiful and safe a place Brussels was. Not anymore, it is from a different world! U.S. must be vigilant and smart," he tweeted.
During an interview on Fox News, Trump said Brussels has transformed from a place of tranquility to an "armed camp."
"Twenty years ago, like a magical city, now you look at it its an armed camp, looking at pictures on TV now it's horrible," he said. "You want to lead your life, not live in armed camp, and certain group is making living a normal life impossible."
Democratic Presidential candidate Hillary Clinton tweeted her response as well.
Ohio Gov. John Kasich said he was "sickened by the pictures of carnage."
Ted Cruz released a statement saying Radical Islam is "at war with us."
"For over 7 years we have had a president who refuses to acknowledge this reality," he wrote.
European leaders also took to Twitter to react to the events.