President Trump nominated White House Deputy Chief of Staff Kirstjen Nielsen to be the new Secretary of Homeland Security.

If confirmed, Nielsen would replace White House Chief of Staff John Kelly, who Kelly served as Trump's DHS chief for just six months before replacing Reince Priebus as chief of staff. Elaine Duke has been serving as acting DHS secretary.

Nielsen would be the first former DHS staffer to lead the department.

Neilsen is an expert in homeland and national security policy. She previously worked as a special assistant to George W. Bush and for the Transportation Security Administration.

Nielsen is also a recipient of Security magazine's 2016 Most Influential People in Security recognition.