The Trump administration's move to separate immigrant parents from their children on the U.S.-Mexico border has grabbed attention around the world, drawn scorn from human-rights organizations and overtaken the immigration debate in Congress.

It's also a situation that has been brewing since the week U.S. President Donald Trump took office, when he issued his first order signalling a tougher approach to asylum-seekers. Since then, the administration has been steadily eroding protections for immigrant children and families.

"They're willing to risk harm to a child being traumatized, separated from a parent and sitting in federal detention by themselves, in order to reach a larger policy goal of deterrence," said Jennifer Podkul, director of policy at Kids in Need of Defence, which represents children in immigration court.

To those who work with immigrants, the parents' plight was heralded by a series of measures making it harder for kids arriving on the border to get released from government custody and to seek legal status in the U.S.

In the U.S. asylum seekers have watched helplessly as their children have been taken away from them under Donald Trump's new zero tolerance immigration policy. The CBC’s Wendy Mesley speaks with Natalia Cornelio, director of criminal justice reform for Texas Civil Rights Project, about the stories she’s hearing from parents. 6:20

The administration says the changes are necessary to deter immigrants from coming here illegally. But a backlash is mounting, fuelled by reports of children being taken from mothers and distraught toddlers and elementary school age children asking, through tears, when they can see their parents.

Lawmakers to meet this week

Kellyanne Conway, a counsellor to the president, on Sunday distanced the Trump administration from responsibility for separating migrant children from their parents.

Conway rejected the idea that Trump was using the kids as leverage to force Democrats to negotiate on immigration and his long-promised border wall, even after Trump tweeted Saturday: "Democrats can fix their forced family breakup at the Border by working with Republicans on new legislation, for a change!"

Trump plans to meet with House Republicans on Tuesday to discuss pending immigration legislation amid an election-season debate over an issue that helped vault the New York real estate mogul into the Oval Office in 2016. The House of Representatives is expected to vote this week on a bill pushed by conservatives that may not have enough support to pass, and a compromise measure that the White House has endorsed.

A boy and father from Honduras are taken into custody by U.S. Border Patrol agents near the U.S.-Mexico Border on June 12 near Mission, Texas. The asylum seekers were then sent to a customs processing centre for possible separation. U.S. border authorities are executing the Trump administration's 'zero tolerance' policy toward undocumented immigrants. (John Moore/Getty Images)

To California Rep. Adam Schiff, the administration is "using the grief, the tears, the pain of these kids as mortar to build our wall. And it's an effort to extort a bill to their liking in the Congress."

Schiff called the practice "deeply unethical" and said Republicans' refusal to criticize Trump represented a "sad degeneration" of the GOP, which he said had become "the party of lies."

Conway, however, put the onus on Democrats, saying if there are serious about overhauling the system, "they'll come together again and try to close these loopholes and get real immigration reform."

Asked whether the president was willing to end the policy, she said: "The president is ready to get meaningful immigration reform across the board."

Constructed on Friday, the so-called 'tent city' was created to housed unaccompanied minors who crossed the U.S.-Mexico border. (CBC)

Texas Rep. Beto O'Rourke said he was working on legislation that would end the practice of family separation.

Speaking from Texas, where he was leading a march to a town where a new tent structure for children recently opened, O'Rourke said "we can do the right thing by this country and for those kids, and not do it at the price of a 2,000-mile (3,200 km), 30-foot-high (9-metre), $30-billion wall, not doing it at the price of deporting people who are seeking asylum, deporting people in some cases back to certain death, not doing it at the cost of ending family migration, which is the story of this country."

Constructed on Friday, the so-called "tent city" was created to house unaccompanied minors who crossed the U.S.-Mexico border. These typically older children are being taken to the 400-bed facility in order to free up space in other centres where younger children who were separated from their parents are taken.

2,000 children separated in 6 weeks

About 2,000 children had been separated from their families over a six-week period ending in May, administration officials said Friday.

Among the parents caught up in the new rules is 29-year-old Vilma Aracely Lopez Juc de Coc, who fled her home in a remote Guatemalan village after her husband was beaten to death in February, according to advocates. When she reached the Texas border with her 11-year-old son in May, he was taken from her by border agents, she said.

The Trump administration's move to separate immigrant parents from their children on the U.S.-Mexico border has drawn denunciation from the United Nations, Roman Catholic bishops and countless humanitarian groups. (Butch Comegys/Associated Press)

Her eyes swollen, she cried when she asked a paralegal what she most wanted to know: When could she see her son again?

"She did not know what was going on," said paralegal Georgina Guzman, recalling their conversation at a federal courthouse in McAllen, Texas.

Antar Davidson is a former worker at the shelters who has seen firsthand how hard the separations are for children.

He recounted an instance where three siblings from Brazil — aged 16, 10 and six — were being separated at a facility and made to sleep in separate bedrooms.

"The two younger siblings were grasping the [oldest] brother and desperately trying to hold on to him," he told CBC News.

Antar Davidson quit his job at a youth migrant shelter in Arizona after 5 months because he says he was placed in situations and told by superiors to do things that were against his morals 7:38

"They were all just tearing… weeping and I just said to the brother, I said in Portuguese, I said, 'Try and be strong, I know it's a hard time.'

"He looks at me with tears streaming down his face and said, 'How? How can I be strong? I don't know where my mother is. I don't know what to tell my brother and sister.'"

Similar scenarios play out on a daily basis in federal courtrooms in Texas and Arizona, where dozens of immigrant parents appear on charges of entering the country illegally after travelling up from Central America. More than the legal outcome of their cases, their advocates say, they're worried about their children.

Since Trump's inauguration, the administration has issued at least half a dozen orders and changes affecting immigrant children, many of them obscure revisions. The cumulative effect is a dramatic alteration of immigration policy and practice.

The measures require a senior government official to sign off on the release of children from secure shelters and allow immigration enforcement agents access to information about sponsors who sign up to take the children out of government custody and care for them.

'Zero tolerance' began in April

The crackdown expanded in April, when the administration announced a "zero tolerance" policy on the border to prosecute immigrants for entering the country illegally in the hopes they could be quickly deported and that the swift deportations would prevent more people from coming.

Parents are now being arrested and placed in quick federal court proceedings near the border. Since children cannot be jailed in federal prisons, they're placed in shelters that have long existed for unaccompanied immigrant children arriving on the border alone.

Critics of U.S. government policy which separates children their parents when they cross the border illegally from Mexico protest during a 'Families Belong Together March', in downtown Los Angeles on June 14. (Robyn Beck/AFP/Getty Images)

The administration insists the new rules are necessary to send a message to immigrants.

"Look, I hope that we don't have to separate any more children from any more adults," Attorney General Jeff Sessions said last week. "But there's only one way to ensure that is the case: It's for people to stop smuggling children illegally. Stop crossing the border illegally with your children. Apply to enter lawfully. Wait your turn."

Immigration on the southwest border has remained high since the zero-tolerance policies took effect. Border agents made more than 50,000 arrests in May, up slightly from a month earlier and more than twice the number in May 2017. About a quarter of arrests were families travelling with children.

White House press secretary Sarah Sanders cited the Bible to defend a border policy that has separated children from their parents. 0:52

In addition to those trying to cross on their own, large crowds of immigrants are gathered at border crossings each day to seek asylum. Some wait days or weeks for a chance to speak with U.S. authorities. On a Texas border bridge, parents and children have been sleeping in sweltering heat for several days awaiting their turn.

Under U.S. law, most Mexican children are sent back across the border. Central American and other minors are taken into government custody before they are mostly released to sponsors in the United States.

The arrival of children fleeing violence in Central America is not new. Former president Barack Obama faced an even larger surge in border crossings that overflowed shelters and prompted the authorities to release many families. Nearly 60,000 children were placed in government-contracted shelters in the 2014 fiscal year.

Under U.S. law, entering the country illegally is a crime. But children, as minors, wouldn't be charged. And the Democrats did not enact a law to separate children from their parents at the border if crossing illegally.

The White House has blamed the Democrats for failing to act on immigration legislation in the past, saying it has led to what it calls the current border crisis.

But the Republicans currently control Congress and the "zero tolerance" immigration policy — including the decision to separate kids and parents — was the brainchild of the Trump administration.