Sen. Kamala Harris (D-CA) called on Homeland Security Secretary Kirstjen Nielsen to resign on Monday, citing her track record of enforcing President Donald Trump’s “anti-immigration agenda” and leading the “failed response” to the devastation in Puerto Rico.

Harris also cited a lack of transparency within the department and Nielsen’s routine failure “to provide complete answers to questions from me and my colleagues” on the Homeland Security Committee.

Nielsen has come under increased scrutiny in recent days for her response to media reports on the conditions at immigration processing centers along the U.S.-Mexico border. Under Attorney General Jeff Sessions, border security agents have been given authority to arrest and criminally charge anyone who crosses the border illegally, resulting in thousands of children being separated from their parents.

On Sunday, Nielsen tweeted that the U.S. does not have a family separation policy, only to walk it back Monday by claiming the U.S. “will not apologize” for ripping families apart in order to enforce laws. She followed President Donald Trump’s rhetoric, calling on Congress to “change the laws” of immigration and “close the loopholes.”

Read Harris’ full statement below: