"We must be together regardless of nationality or race or faith in fighting against the scourge of terrorism. We can and we will defeat those who threaten the safety and security of people all around the world," he said, speaking in the Cuban capital Havana.
"The thoughts and the prayers of the American people are with the people of Belgium and we stand in solidarity with them in condemning these outrageous attacks against innocent people," said Obama.
A series of explosions ripped through Brussels airport and a metro train, killing around 35 people and injuring more than 200 in the latest attacks to rock Europe.