The 53-second ad featured in a Halloween Trump tweet juxtaposes footage of cop-killing illegal immigrant Luis Bracamontes with the approaching Central American caravan, implying that similarly violent criminals may be among those seeking asylum in the United States.
Trump has claimed that "criminals and unknown Middle Easterners" are among the migrants, while the Department of Homeland Security said last month that "gang members" and people with "significant criminal histories" are traveling among the caravan.
Meanwhile, a caravan participant interviewed by Fox News admitted that he had fled Honduras to escape an attempted murder charge.
On Saturday morning, Donald Trump Jr. tweeted: "CNN refused to run this ad... I guess they only run fake news and won't talk about real threats that don't suit their agenda. Enjoy. Remember this on Tuesday," to which CNN responded: "CNN has made it abundantly clear in its editorial coverage that this ad is racist. When presented with an opportunity to be paid to take a version of this ad, we declined. Those are the facts."