The Trump administration loves gaudy numbers like this. Common sense tells you that's a lot of movement in too short of time. Until they release evidence of these numbers, please do not spread this misinformation.
> A recent study from the United Nations reported that President Trump’s immigration policies led to a 97% reduction in illegal aliens heading northbound to the U.S. from Central America.
And you find that the document they link does not support their assertion, and in face the "97%" refers to:
> The migrants who returned during the period were primarily Venezuelan nationals, accounting for 97% of the documented southward flow, with most heading to neighboring Colombia.
It's comically bad deception, only people who continuously traffic in lies all day long would even publish something like this.
Like, say we assume it's true: There are 340 million people in the US. That's less than 1% of the current population leaving. I really doubt anybody would notice much of a difference.