“Chicago is an example – it’s worse than Afghanistan,” said Trump, before also citing Detroit, Oakland and Baltimore.
“They want help. These cities are like living in hell. ”
The president blamed the violence in these cities on their democratic mayors.
In Chicago last weekend, at least nine people – including four children – were killed and 51 others injured in a series of shots.
Earlier this month, the City of the Winds had its deadliest day in about six decades, when 18 people were murdered.
Trump has also expressed support for the arrest and search, a controversial police practice that New York City has used for years to reduce crime.
He credited former mayor Rudy Giuliani – now his personal lawyer – for using the tactic effectively.