And it's not just America' pediatricians, every living formerst lay dill has now weighed in this. But presiderump is not backing dotonight. Abc'nior white house correspondent Cecilia Vega pressing the white H just moments ago. Reporteven in the face of growing outrage, president trump today staunchly defended his administration's policy of separating migrant children their parents. The United States will not be a migrant camp and it not be a refee holding facility. It won't be. Repter: And on Twitter, he is amping up the anti-immigration rhetoric, sayi"big mistake made all over Europe in allowin millions of people in who have so strongly and violently changed their cuure!" The president warning it happere. Still, he says, he, too, isdisturbed those images of children in detention enters. What's happening is so sad, is so and it can be taken care of quy, beautifully, and we'll have safety. Reporter: The president cou be the one to end it. It is his policy launched by administration. Antonight, opposition is Moun. All four LIV former first ladies going public. Laura bush writing in he Washington post," "This zero toerance policy is cruel. Its immoral. And it break heart." Chelle Obama's retweeting Mrs. Bush's -Ed, adding "Sometimes truth transcends party. Rosalynn cter calling the policy "Disgceful and a shame to our cou." Hillarclinton took on the administration's false claim that they areimply enforcing the law. Separating families is not mandated by law at all. That is an outright lie. Reporter: A also took on Aney general Jeff sessions, whitedhe bible as justication. I would C the apostle Paul and his clearnd wise command in Romans 13 Tobey the laws O the government. Those W selectively use the bible to justify this cruelty are ignoring a centralant of christianity. Sus said, uffer the little children unto me." He didsay, "Let the childrsuffer." Reporte even the current first lady, Melania trump, made the rare move intervening on policy, calling on bothides of the aisle to com together, but Ng, "We need to be a count that follows all laws, but also try that governs with heart." Now, with white house under fire, homeland security Seary kooirstjen Nielsen joining a late briefing T defend the pocy. Have youeen the photos of children cages? Have you heard the audio clip ofthese children wing that just came out today? I have -- I have not se something that came out today I've been to detenti centers, and again, ild Ference you to our standards, I would referenou to the care provided,ot just the department of homeland security, but by the department of health and human serviceshen they get to HHS. Reporter: But is that the imagf this country thatou want outre? Children in cages? The image I wanis an immigrn system that secure borders and hutarian ideals ancongress needs to fix it. Cecilia Vega joining us tonight from white house. You just got out O that briefing.the white house nceding a ground with you. And tomorrow, the predent heads to capitol hill Reporter: The white house says the president doesn't want a band-aid fix to this issue, immigration has vexed this city for so many ars, there I absolutely no indication Thi current crisis on the border will force a breakthrough a time soon. David? Cecilia, thank U. Next here, to the severe