Must Stop People From Crossing Border Like Going To "Disneyland": Trump

US President Donald Trump said Tuesday he won't resume separating children of undocumented migrants, but insisted the policy does prevent people from treating illegal border crossings like a trip to "Disneyland."

"We're not looking to do it," he told reporters at the White House.

However, Trump said the practice, which ended in June 2018 under heavy political and legal pressure, had in fact been useful in stemming the flow of illegal immigrants across the US-Mexican border.

"I'll tell you something: once you don't have it, that's why you have many more people coming," Trump said of migrants and asylum seekers.

"They are coming like it's a picnic, like 'let's go to Disneyland,'" Trump said. Just last week he referred to the asylum process as a "hoax."

Trump's battle to prevent illegal immigration and soaring numbers of asylum seekers has turned into the biggest political fight in the country ahead of next year's presidential election.

The Republican is pushing hard for construction of hundreds of miles of new border wall and layers of razor wire. He says that the United States is "full" and cannot take any more migrants or even people fleeing violence in Central America.

On Sunday, Trump abruptly announced the departure of the official in charge of fighting illegal immigration -- Homeland Secretary Kirstjen Nielsen.

According to US media reports, Trump's reshuffle could herald even harsher measures on the southern border.

Confusion and rhetoric

But Trump's latest comments reflect the confused nature of the White House's messaging on the sensitive immigration issue.

Trump claimed that he never wanted children to be taken away from their parents when they crossed the border illegally or sought asylum. Instead he blamed this on his Democratic predecessor Barack Obama.

"Just so you understand, President Obama separated the children. Those cages that were shown -- I think they were very inappropriate -- were by President Obama's administration, not by Trump. President Obama had child separation," Trump said.

"You know it. We all know it. I'm the one who stopped it," he said.

Obama did crack down on illegal immigration, resulting in large numbers of deportations and children were detained along with their parents.

However, Trump hugely accelerated the tough measures with a so-called zero-tolerance policy.

This meant that anyone crossing illegally would face automatic prosecution, leading to jailing of adults and immediate separation of their children.

Before, families with children were largely allowed to stay together, whether on bail, in custody or being deported.

By the time Trump's policy was halted, thousands of children had been removed and placed in temporary accommodation, leading to harrowing images and reports of administrative chaos in which parents were later unable to find their children.

Last week, Trump threatened to impose steep import tariffs on Mexican automobiles if Mexico does not do more to stop would-be migrants on their trek north to the US border.

However, the timing and practicalities of this were unclear.

Previously, Trump said he would shut down the entire border to stop immigrants entering, but he then backed off in the face of worries over the economic impact.

Another controversial policy of automatically returning asylum seekers to wait in Mexico was blocked Monday by a federal judge in California.

The White House issued a statement Tuesday condemning the ruling and saying it would appeal.

The court impedes the president's ability to stop an influx "crashing our immigration system and overwhelming our country," Trump's press office said.