CNN's report came just as a federal judge in Californiablocked Trump's policyof forcing some asylum-seekers to return to Mexico as they await a court appearance.
The Republican is pushing hard for construction of hundreds of miles of new border wall and layers of razor wire. Most Americans, though, seem to recognize that immigrants are not more likely than American citizens to commit crimes: 54 percent say that immigrants are unlikely to commit more crime, compared with 30 percent who say they are more likely to do so.
Trump's comments on Wednesday came as the immigration debate ramps up on the southern border and in Washington. Senate Democrats are pursuing multiple tracks, including exploring whether talks with the White House might be feasible.
This includes migrants who claim to be children, but who are actually 18 or older, as well as adults who falsely claim to be parents of minors they're traveling with, according to Brian Hastings, chief of law enforcement operations for Customs and Border Protection. Instead he blamed this on his Democratic predecessor Barack Obama.
"President Obama had child separation, take a look, the press knows it, you know it, we all know it", Trump said in the clip. "And I think they will pay a very big price in 2020 for all of the things", Trump said. "They want to know what they can do today to hit Donald Trump". President Obama separated children.
Kirstjen Nielsen Out As DHS Secretary
Some 400,000 migrants were apprehended at the border in the October 2017-October 2018 period, compared to the 1.6 million in 2000. Ms Nielsen's resignation was seized upon by John Delaney, one of the Democratic candidates for the 2020 presidential nomination.
However, Trump hugely accelerated the tough measures with a so-called zero-tolerance policy. While Border Patrol arrests, the most widely used gauge of illegal crossings, have risen sharply over the last year, they are relatively low in historical terms after hitting a 46-year low in 2017.
On Monday, a judge in San Francisco said the Trump administration's policy of sending some asylum seekers to Mexico while their claims worked through a backlogged immigration court system was not authorized by US law. Now, the Trump administration has extended the same policy to the Calexico port of entry in southern California and to the border crossing in El Paso, Texas.
However, the timing and practicalities of this were unclear.
Customs and Border Protection did not say how many fraudulent claims were made in years past for comparison.
Under the new policy, asylum seekers are not guaranteed interpreters or lawyers.
The White House is also considering a legal strategy to trigger a court challenge by simply detaining minors for longer than the 20-day maximum established in the court ruling.
President Trump has said the recent surge is overwhelming the nation's immigration system.