U.S. President Donald Trump said he knows who was behind the terror attacks that targeted his country in September 2001, adding that “Iraq did not knock down the World Trade Centre”.

"It was not Iraq. It were other people. And I think I know who the other people were. And you might also," Trump said in an interview on ABC News.

Trump deemed it as a terrible decision to go into the Middle East, saying that the U.S. military was totally depleted.

"I happen to think it was the worst decision made in the history of our country, going into the Middle East; it's like quicksand."

"Terrible. We're now up to almost $8 trillion. And when we want to build a roadway, a highway, a school, or something, everyone's always fighting over money. It's ridiculous. So that was a bad decision," Trump elaborated.