US president says people entering country without proper documents should be sent back without court cases or judges.

President Donald Trump has said undocumented people entering the United States should be immediately deported without any judicial process, drawing sharp criticism from rights groups who say such a move would be illegal and violate the constitution.

“We cannot allow all of these people to invade our country,” Trump wrote on Twitter on Sunday, as he reiterated his tough stance on immigration.

“When somebody comes in, we must immediately, with no judges or court cases, bring them back from where they came.

“Our system is a mockery to good immigration policy and law and order. Most children come without parents,” he said, adding that immigration must be based on merit.

In response, Omar Jadwat, director of the American Civil Liberties Union’s Immigrants’ Rights Project, called Trump’s suggestion “both illegal and unconstitutional”.

“Any official who has sworn an oath to uphold the constitution and laws should disavow it unequivocally.”

📣 What President Trump suggested here is both illegal and unconstitutional. Any official who has sworn an oath to uphold the Constitution and laws should disavow it unequivocally. https://t.co/qsy58VACSB — ACLU (@ACLU) June 24, 2018

The Council on American-Islamic Relations (CAIR) also condemned the US president’s comments.

“This clear call for an end to the constitutionally-guaranteed right to due process is symptomatic of an administration that disdains both the Constitution and our judicial system, and would subject those who cross our borders to the whims of unaccountable officials acting on the twisted logic of white supremacy and racism,” Nihad Awad, CAIR national executive director, said in a statement.

“All Americans should be outraged by this affront to our values and democracy.”

‘Zero tolerance’

Trump’s latest remarks came as thousands of children wait to be reunited with their parents after the right-wing president signed an executive order ending his administration’s practice of separating families at the border.

Since reversing the tactic on Wednesday, Trump has severely criticised the US immigration laws on Twitter and in speeches.

“Our immigration policy, laughed at all over the world, is very unfair to all of those people who have gone through the system legally and are waiting on line for years!” he tweeted.

The Trump administration has faced increasing criticism over what advisers have claimed is a conscious decision to take minors away from undocumented immigrant parents and guardians.

Roughly 2,300 children were separated from their families in recent weeks by US Border Control.

Following the latest executive order, a federal task force was set up to reunite children and their parents at detention facilities on the Mexican border.

A defiant Trump has, however, said that his “zero tolerance” policy on undocumented immigrants, in which all unlawful border crossings are referred for prosecution, will continue. It is unclear what this means for families. Rights groups have vowed to challenge any policy that detains families together for more than 20 days – the time allowed by the courts to hold children in immigrant detention centres.

US immigration law provides certain rights for undocumented immigrants arrested by Immigration and Customs Enforcement.

In most cases, they are allowed a full hearing before an immigration judge before being deported.