Calling for a "strong" border, he says: "We can not allow our Country to be overrun by illegal immigrants as the Democrats tell their phony stories of sadness and grief, hoping it will help them in the elections".
Earlier, the Trump administration said it knew the location of all children in its custody after it separated them from their families at the southern border and was working to reunite them.
ABC News reported Friday that hundreds of separated migrant families have been reunited since Trump signed the order.
A bipartisan coalition of USA mayors gathered in a Texas border town on Thursday morning to speak out against Trump's immigration crackdown, which they characterized as a "humanitarian crisis".
Republican leaders delayed a vote Thursday on what was billed as a compromise measure to fund border security and address legal status for young immigrants brought to the USA unlawfully as children, as they try to win more support for the bill.
Michelle Brane, a migrant rights director at the Women's Refugee Commission, accused the Justice Department of trying to bypass child welfare laws in its rush to detain migrant families.
Trump's comments come amid an global outcry over the separation of migrant families at the southern border. In one tweet, he used the loaded term "infest" to reference the influx of immigrants entering the country illegally.
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"What has happened on the US-Mexico border is a moment of reckoning as it points to a systemic toxicity in public discourse and action". "We haven't tapped out on the number of adults that have been separated".
Trump backed up his complaint with the unsupported claim that undocumented immigrants are more risky than the general population and shared statistics on crimes committed by undocumented immigrants without any context.
Sen. Chuck Schumer said Sunday that the federal government should appoint the czar until officials reunite all of the families that were separated.
As Democratic congressman Ted Lieu derided the separations as "a functional equivalent of kidnapping", he played the audio into a microphone, to a startled House chamber.
"I think the American people need to hear this", he said.
The Oklahoma Republican says a court settlement limiting child detentions to 20 days is the issue. The crowd chanted "Families belong together" and "No baby jails!"
The incident occurred amid an uproar over the Trump administration's practice of separating immigrant families caught on the southwest border.
Also, Trump is taking a risk by asking Republicans to push off a vote until after the election.
"We have an internal commitment to our members and we are going to fulfill that commitment, that pledge that was made, to turn off the discharge petition", McHenry said.