"They're terrible laws", Trump said of his administration's controversial child separation policy.
Roughly 2,000 minors have been separated from their families over a six-week period ending in May, administration officials said last week.
Press secretary Sarah Sanders delayed her briefing nearly four hours as Kirstjen Nielsen, the homeland security secretary, was flown back from New Orleans to face reporters.
At the border, an estimated 80 people pleaded guilty Monday to immigration charges, including some who asked the judge questions such as "What's going to happen to my daughter?" and "What will happen to my son?" Democratic and Republican members of Congress spoke out against the administration's enforcement efforts over the weekend.
"While these cases are pending, families should stay together".
"All Americans are rightly horrified by the images we are seeing on the news, children in tears pulled away from their mothers and fathers", Cruz said. The Democrats have to change their law.
I challenge anyone in the Trump Administration to listen to this audio and defend the child separation policy. "The practice and policy today of removing children from their parents' care at our border with Mexico is disgraceful and a shame to our country". Accusing the press and advocacy groups of "irresponsible and unproductive misreporting", Nielsen tweeted: As I have said many times before, if you are seeking asylum for your family, there is no reason to break the law and illegally cross between ports of entry.More news: Iran Coach Carlos Queiroz Blasts 'Arrogant' Nike For US Sanctions
"You know they're coming in, they're people that came on merit, not based on a lottery or not people that snuck across the border". He told US attorneys to adopt a "zero tolerance" policy of prosecuting everyone apprehended at the border.
In a rare comment, Mrs Trump spoke against the Trump administration's harsh policy, saying the U.S. needs to be "a country that governs with heart".
Children inside a U.S. Customs and Border Protection detention facility at the Rio Grande Valley Centralized Processing Center in Texas.
Some 2,342 children were separated between May 5 and June 9, Sen. Dianne Feinstein reported, citing Homeland Security numbers. More adults were being jailed as a result, which led to their children being separated from them.
Van Hollen, a Democrat, called the policy of breaking up families who have entered the country illegally "cruel".
Donald Trump has previously blamed a law that "Deomcrats gave us" for the detentions, but it remains unclear which law he means. There are no laws that require children to be separated from their parents, or that call for criminal prosecutions of all undocumented border crossers. Ms Merkel opposes such a ban.
GOP senators, including Lindsey Graham of South Carolina, Jeff Flake of Arizona and Susan Collins of ME, said they were considering legislation that would keep migrant families together; provide additional judges so detained families would face shorter waiting periods; and provide facilities for the families to stay. They said a pilot program under Mr. Obama showed that was effective in getting people to show up for their court dates.