"We have high standards. We give them meals and we give them education and we give them medical care. There are videos, there are TVs," Nielsen said in response to a question from CNN's Jeff Zeleny. "I visited the detention centers myself."She said the "vast majority" of children being held in the detention facilities were sent to the US alone by their parents.Nielsen also responded to criticism from multiple former first ladies to the administration's zero tolerance immigration stance, remarking that it is a serious issue but one that should be handled by Congress. "What my response would be is calling attention to this matter is important," Nielsen said from the White House briefing room Monday. "This is a very serious issue that has resulted after years and years of Congress not taking action, so I would thank them both for their comments. I would thank them both for their concerns. I share their concerns. Congress is the one that needs to fix this."Nielsen added: "It's not a policy. Our policy at DHS is to do what we're sworn to do, which is to enforce the law." Asked specifically about the Japanese internment camps remark from former first lady Laura Bush, Nielsen said: "What I believe is that we should exercise our Democratic rights as Americans and fix the problem. It's a problem. Let's fix it." The administration continued to falsely insist that only Congress can end the practice of separating children from their parents at the US border."We need Congress to fully fund our ability to hold families together through the immigration process. And until these loopholes are closed by Congress, it is not possible as a matter of law to detain and remove whole family units who arrive illegally in the United States," Nielsen said.Pressed on why rates of separation are higher now compared to past administrations, Nielsen insisted Trump's hands were tied."I think the President is trying to find a long-term fix. So why don't we have Congress change the laws?" she said.She denied that children were being used as a "pawn" in negotiations on Capitol Hill over an immigration measure that would include funding for Trump's promised border wall."The children are not being used as a pawn," she said. "We're trying to protect the children, which is why I'm asking Congress to act."