Donald Trump has renewed his call for a ban on Muslims entering America in the wake of the Brussels attacks.

“This all happened because frankly there is no assimilation,” he said on Fox and Friends on Tuesday morning, just hours after the Belgian city was rocked by the blasts. "They don't want laws that we have, they want Sharia Law and you say to yourself, 'At what point? How much of this do you take?'

"What we are doing is allowing thousands and thousands of these people into our country and we are going to have nothing but problems as sure as you are sitting there.”

He added: “Brussels was a beautiful city, a beautiful place with zero crime. And now it's a disaster city. It's a total disaster, and we have to be very careful in the United States, we have to be very careful and very vigilant as to who we allow in this country. "

The attackers have not been identified but Trump linked the acts of terror to Muslim refugees and migrants who have been living in parts of Europe since escaping Syria.

“It's going to get worse and worse. In my opinion, this is just the beginning. It will get worse and worse because we are lax and we are foolish -- we can't allow these people, at this point we cannot allow these people to come into our country. I'm sorry," he said. "This is a story that just seems to be more and more happening and it's really not very pretty to watch."

President Obama took a different approach as he spoke about the attacks during a speech in Havana, Cuba on Tuesday morning.

"It is a reminder that the world must unite, we must be together ... in fighting against the scourge of terrorism," he said.