His briefing was broadcast on Twitter at the White House.
"The Department of Homeland Security and the US Department of Justice will establish a joint operations center to investigate violent civil unrest involving radical leftists," Trump said.
More than 200 people were arrested in various cities during the riots in the United States, he said.
Earlier, Trump confirmed his intention to visit the city of Kenosha, where the protests are taking place, despite a request from State Governor Tony Evers to cancel the trip.