President Obama was briefed on the Brussels terrorist attacks while on his trip in Cuba on Tuesday. A White House official said that Obama along with Homeland Security Advisor, Lisa Monaco and other U.S. officials have been in close contact with Belgian authorities, since the attacks.
"The President reaffirmed the steadfast support of the United States for Belgium, and offered any assistance necessary in investigating these attacks and bringing those responsible to justice," the White House said.
At least 31 people were killed Tuesday in explosions at the Brussels airport and the subway system, with ISIS recently claiming responsibility for the attacks.
"We stand in solidarity with them in condemning these outrageous attacks against innocent people," Obama said in Havana. As he commented on the Brussels attacks at the top of a keynote address to the Cuban people at the t the Grand Theater of Havana. "We can and we will defeat those who threaten the safety and security of people all around the world," he said.
Three American missionaries from Utah were among those seriously injured in the airport attack and have been hospitalized, Mormon Church officials, said.
Secretary of State John Kerry, spoke by telephone, from Cuba, with the Belgian foreign minister, and said in a statement that the U.S. was working "to determine the status of all American citizens in Brussels." .Obama had also telephoned Belgium Prime Minister Charles Michel to offer his condolences.
Gallery: Brussels Blasts Kill Dozens in Airport and Subway Attacks
The Associated Press and Reuters contributed to this report.