U.S. President Donald Trump on Thursday officially nominated his current deputy chief of staff, Kirstjen Nielsen, to serve as his Homeland Security secretary.

Nielsen previously worked as chief of staff to John Kelly — Trump's current White House chief of staff —when Kelly served as Trump's first DHS secretary. Trump said Nielsen's appointment would make her the first former DHS employee to run the entire agency.

"I know you will fulfill your duties with dedication, determination and resolve. And I know you will never waver in fulfilling your obligations to the citizens, the laws and the country we all took an oath to protect," Trump said.

Nielsen is a close confidant of Kelly and an expert in national security policy. Earlier in her career, she worked as a special assistant to former President George W. Bush.

In accepting the nomination, Nielsen said she hopes to "live up to the standards the American people expect and deserve."

Her nomination must now be confirmed by a vote in the Senate.

Quick Facts: Who is Kirstjen Nielsen?

Nominee: Secretary of Homeland Security, awaiting Senate confirmation

Education: B.S. from Georgetown University, J.D. from University of Virginia School of Law


  • Senior fellow, Georgetown School of Foreign Center for Cyber and Homeland Security
  • Chair, Global Agenda Council on Risk and Resilience of the World Economic Forum
  • Founder, Sunesis Consulting, providing strategic national and homeland security to governments.

Government experience:

  • Special assistant to President George W. Bush
  • Director for prevention, preparedness and response at the White House Homeland Security Council
  • Headed the Transportation Security Administration's Office of Legislative Policy and Government Affairs
  • Deputy Chief of Staff at the White House