WASHINGTON:U.S. President Joe Biden on Tuesday ordered a review of asylum processing at the U.S.-Mexico border and the immigration system as he seeks to undo some of former President Donald Trump's hardline policies.

Biden also created a task force to reunite migrant families who were separated at the border by Trump's 2018 'zero tolerance' strategy.

"We are going to work to undo the moral and national shame of the previous administration that literally, not figuratively, ripped children from the arms of their families," Biden said, as he signed the three immigration-related executive orders at the White House.

The executive orders called for a dizzying array of reviews and reports that could trigger policy changes in the weeks and months ahead, but provide limited immediate relief to immigrants barred by Trump-era rules.

Immigration advocates have urged the new Democratic administration to quickly undo Trump's policies but Biden aides say they need time to unravel the many layers of immigration restrictions and to put in place more migrant-friendly systems.

"It's not going to happen overnight," White House Press Secretary Jen Psaki said earlier in the day.

The cautious strategy reflects the tightrope Biden is walking to reverse hardline Trump policies while simultaneously trying to prevent a surge in illegal immigration. Biden opponents could also derail or slow down his agenda with lawsuits if his administration moves too quickly and fails to follow proper procedures.

In a sign of the wary approach, Biden's executive orders on Tuesday did not repeal an order known as 'Title 42,' which was issued under Trump to stop the spread of the coronavirus and allows U.S. authorities to expel almost all people caught crossing the border illegally.

He did, however, mandate a review of the Migrant Protection Protocols (MPP), a Trump program that ordered 65,000 asylum seekers to wait in Mexico for their U.S. court hearings.

The Biden administration has stopped adding people to the program but has not yet outlined how it will process the claims of those already in it.

Across the border in Mexico, migrants enrolled in MPP said they were anxious for news about Biden's plans for the program.

"I don't understand why he doesn't just say what he's going to do," said Cuban asylum seeker Yuri Gonzalez, who has been waiting for over a year in Ciudad Juarez.

Chad Wolf, former acting U.S. Department of Homeland Security secretary under Trump, said in an interview that halting the MPP program was a mistake because it had been an effective deterrent to illegal immigration.

"If you do have a surge (of migrants), you're taking one of your tools off the table," he said in reference to the program.

Michelle Brane, a senior director with the New York City-based Women's Refugee Commission, said advocates had been hoping for Biden's orders to be "more immediate and operational," but that they would "wait and see" what concrete steps U.S. immigration agencies take to implement the directives.

CHANGE IN RHETORIC

The tone of Biden's orders on Tuesday differed dramatically from Trump's incendiary immigration rhetoric depicting asylum seekers as a security threat or an economic drain on the United States.

"Securing our borders does not require us to ignore the humanity of those who seek to cross them," reads the order dealing with asylum.

But opposition from Republicans continues and lawsuits by conservative groups could potentially slow down Biden's agenda. A federal judge last week temporarily blocked one of his first immigration moves - a 100-day pause on many deportations - after the Republican-led state of Texas sought an injunction.

Trump won the presidency in 2016 while making border security a major theme of his campaign. If Biden fails to prevent surges in illegal immigration at the U.S.-Mexico border, he could give ammunition to Republicans in the 2022 congressional elections, said Sarah Pierce, a policy analyst with the Washington-based Migration Policy Institute.

"This is the thing that rallied Donald Trump supporters," she said.

Biden, on the other hand, pledged in his 2020 election campaign to move quickly to reunite parents and children separated at the southern border and the task force set up on Tuesday is aimed at fulfilling that promise.

However, it will face a daunting challenge in trying to track down the parents of more than 600 children who remain separated, according to a January court filing in a related case. The children are living with relatives or in foster care, an attorney representing plaintiffs in the litigation told Reuters.

The task force will be led by Alejandro Mayorkas, one of the senior officials said on Monday. The U.S. Senate on Tuesday confirmed Mayorkas as the new head of the Department of Homeland Security, the first Latino and immigrant to hold that position.

Biden's executive orders on Tuesday also called for a review of Trump's so-called 'public charge' rule, which makes it harder for poorer immigrants to obtain permanent residency in the United States.

The review is expected to start the process to rescind it, according to two people familiar with the plan.