President Donald Trump listens during a meeting with Republican members of Congress on immigration in the Cabinet Room of the White House, Wednesday, June 20, 2018, in Washington. (AP Photo/Evan Vucci)
Evan Vucci/AP
President Donald Trump listens during a meeting with Republican members of Congress on immigration in the Cabinet Room of the White House, Wednesday, June 20, 2018, in Washington. (AP Photo/Evan Vucci)
Now playing
03:14
Confusion continues over immigration policy
Libre by Nexus
Now playing
02:25
Moment Guatemalan mother reunites with son
Now playing
04:16
The fight over immigration is decades old
TIJUANA, MEXICO - JUNE 21:  A migrant mother walks with her two daughters on their way to cross the port of entry into the U.S. for their asylum hearing on June 21, 2018 in Tijuana, Mexico. The mother, who did not wish to give their names, said they were fleeing their hometown near the Pacific coast of Mexico after suffering a violent carjacking of her taxicab. The Trump Administration's controversial zero tolerance immigration policy led to an increase in the number of migrant children who have been separated from their families at the southern U.S. border. U.S. Attorney General Jeff Sessions has added that domestic and gang violence in immigrants' country of origin would no longer qualify them for political asylum status.  (Photo by Mario Tama/Getty Images)
Mario Tama/Getty Images South America/Getty Images
TIJUANA, MEXICO - JUNE 21: A migrant mother walks with her two daughters on their way to cross the port of entry into the U.S. for their asylum hearing on June 21, 2018 in Tijuana, Mexico. The mother, who did not wish to give their names, said they were fleeing their hometown near the Pacific coast of Mexico after suffering a violent carjacking of her taxicab. The Trump Administration's controversial zero tolerance immigration policy led to an increase in the number of migrant children who have been separated from their families at the southern U.S. border. U.S. Attorney General Jeff Sessions has added that domestic and gang violence in immigrants' country of origin would no longer qualify them for political asylum status. (Photo by Mario Tama/Getty Images)
Now playing
03:39
Tapper fact-checks DHS on family separations
Sara Sidner/CNN
Now playing
01:05
Foster mom describes kids' anxiety, terror
ABC/Jimmy Kimmel LIVE!
Now playing
01:36
Late night mocks Trump's immigration reversal
forced separate children parents border reporters notebook orig js zw ms al_00000616.jpg
forced separate children parents border reporters notebook orig js zw ms al_00000616.jpg
Now playing
04:07
What zero tolerance really looks like
U.S. Secretary of Homeland Security Kirstjen Nielsen speaks on migrant children being separated from parents at the southern border during a White House daily news briefing at the James Brady Press Briefing Room of the White House June 18, 2018 in Washington, DC. Nielsen joined White House Press Secretary Sarah Sanders at the daily news briefing to answer questions from members of the White House Press Corps.
Alex Wong/Getty Images
U.S. Secretary of Homeland Security Kirstjen Nielsen speaks on migrant children being separated from parents at the southern border during a White House daily news briefing at the James Brady Press Briefing Room of the White House June 18, 2018 in Washington, DC. Nielsen joined White House Press Secretary Sarah Sanders at the daily news briefing to answer questions from members of the White House Press Corps.
Now playing
01:18
Protesters confront Secy. Nielsen at restaurant
A mother and her children walk outside the refugee house they stayed in after being released from detention
Claudia Morales
A mother and her children walk outside the refugee house they stayed in after being released from detention
Now playing
05:29
Families held after border crossing
immigrant families separated border fact check tapper orig_00011408.jpg
immigrant families separated border fact check tapper orig_00011408.jpg
Now playing
03:58
Fact-checking Trump's claim on family separation
CNN —  

Protests along the US-Mexico border heated up again Monday as thousands of undocumented migrant children remained separated from their parents.

One of the main protests is taking place in the Texas border city of Tornillo, the site of a temporary shelter for unaccompanied migrant children.

Another protest is happening outside the US Border Patrol Central Processing Center in McAllen, Texas. There, demonstrators held signs such as “Parents Everywhere Care” and “Free Them.”

Protesters gathered Monday to denounce the separation of migrant children and their parents.
CNN
Protesters gathered Monday to denounce the separation of migrant children and their parents.

After widespread criticism over family separations caused by President Donald Trump’s “zero tolerance” policy, Trump reversed course last week by signing an executive order aimed at keeping some families together at the border.

But it did little to calm the outrage. And on Sunday, Trump called for the deportation of people without judicial proceedings to thwart what he referred to as an invasion by “these people.”

More than 2,000 children who have been separated from their families still await reunions with their parents. The Department of Homeland Security released a plan for putting back together the thousands of families on Saturday night, but it appears the reunions won’t happen quickly.

On Sunday, celebrities including Lena Dunham, Sia and Amber Heard joined protests in the border city of Tornillo, the site of a US-Mexico border checkpoint and a temporary shelter for unaccompanied migrant minors.

Other cities along the border have also been the site of protests. Chanting protesters in McAllen briefly blocked a bus leaving a migrant detention center as they yelled “set the children free” and “shame on you” at Border Patrol officers on Saturday.

Demonstrator Martha Mercado tried to stop a bus with immigrant children outside a Border Patrol processing center in McAllen, Texas.
David J. Phillip/AP
Demonstrator Martha Mercado tried to stop a bus with immigrant children outside a Border Patrol processing center in McAllen, Texas.

Massachusetts Democratic Sen. Elizabeth Warren visited the center in McAllen on Sunday. “It’s a disturbing picture,” she said after her visit.

“They’re all on concrete floors in cages.”

After days of confusion, the Trump administration released its plan for reuniting children still in the custody of Health and Human Services over the weekend.

Under the plan, children will be kept in custody and returned to family members only after the parents’ deportation proceedings are completed. The families will be reunited before they are deported, or if the parent is released from detention, after the parent applies to serve as the child’s sponsor.

Parents are being offered the option to sign voluntary departure orders to speed up their cases and are told they’ll be reunited with their kids before they are deported if they do – a move that has raised questions from lawyers who represent undocumented immigrants.

CNN’s Faith Karimi, Eric Levenson, Tal Kopan, Eli Watkins, Holly Yan, Meg Wagner and Brian Ries contributed to this report.