Sen. Kamala Harris said that Secretary of Homeland Security Kirstjen Nielsen should resign as outrage over the White House's "zero tolerance" immigration policy, which has separated undocumented parents and children, grows.

Harris, a Democrat, sits on the Senate Committee on Homeland Security and Governmental Affairs, which has oversight of DHS.

Here's her tweet:

Earlier today, Nielsen defended the immigration policy, saying, "We will not apologize for the job we do."

You can watch more of her comments in the video below: