The overall murder rate in the US's 30-largest cities in 2016 climbed "by double digits," he said, adding that the violent crime rate has ticked up in "many of our big cities."
The President added that "more than 4,000 were shot last year alone" in Chicago.
"We've allowed too many young lives to be claimed, and you see that, you see that all over," Trump said in his speech Wednesday before a gathering of major city police chiefs as he made the case for tougher law enforcement policies.
"This is a national tragedy and it requires national action. This violence must end and we must all work together to end it," Trump said, also correctly adding that 60% of murder victims under the age of 22 are African-American
Trump's comments Wednesday came a day after he falsely claimed that the US murder rate is at a 47-year record-high
-- a figure he incorrectly cited repeatedly on the campaign trail. 2015 brought the largest increase in the national murder rate in about half-a-century, but the national murder rate is still lower than it was 47 years ago.
The President was quick to place blame for the crime increases -- without citing evidence -- on undocumented immigrant gang members.
"We'll take that fight to the drug cartels and work to liberate our communities from their terrible grip of violence. You have the power and knowledge to tell (Homeland Security Secretary John Kelly) who the illegal immigrant gang members are," he said.
Trump put his trust in the local law enforcement leaders gathered, saying the federal government could never be so precise and they knew the "good ones" and the "bad ones."
"And we'll get them out of our country and bring them back where they came from and we'll do it fast," he said.
But while Trump on Wednesday leaned on factual statistics to make his case that the US needs tougher crime policies, his statistics omitted important context and ignored statistics that paint a different picture than the one of doom and gloom that helped his successful campaign's "law and order" message gain traction.
The President reiterated a campaign trail promise that he has a zero tolerance policy for acts of violence against law enforcement.
"We must protect those who protect us," he said. "It's not fair."
Violent crime saw a roughly 4% uptick in 2015 from the previous year. Still, overall crime continued to decline.
And despite the uptick in violent crime in 2015, violent crime has been on the decline for years.
The Brennan Center, which gathered crime data on the 30 largest US cities and is responsible for the figure Trump cited, noted that "violent crime still remains near the bottom of the nation's 30-year downward trend."
"The 2016 murder rate is projected to be 14 percent higher than last year in the 30 largest cities," the Brennan Center said in its December 2016 report. "Chicago is projected to account for 43.7% of the total increase in murders."