Also on Saturday an off-duty police officer shot dead a suspected attacker who stabbed nine people inside a mall located in the US city of St. Cloud, Minnesota.
"I think maybe we are going to see a big change over the next couple of days. I think this is something that maybe… will happen, perhaps, more and more over the country," Trump told FOX News speaking about possible terror attacks across the United States.
He added that the country was becoming more weak and criticized the US leadership, which had been classified as "stupid."
Trump has sparked controversy in the country with his comments on Muslims, women, and migration, including calls to build a wall with Mexico and temporarily ban Muslims from entering the United States.