US President Donald Trump was expected to nominate Kirstjen Nielsen, an aide to White House chief of staff John Kelly, to lead the Department of Homeland Security, a White House official said on Wednesday.
Nielsen is now the White House principal deputy chief of staff.
The White House says Nielsen has "extensive professional experience in the areas of homeland security policy and strategy, cybersecurity, critical infrastructure and emergency management".
The official announcement could come as soon as Wednesday, although the officials cautioned nothing is set until Trump publicly announces her as the pick.
If confirmed by the Senate, Nielsen would take the reins at a sprawling department with more than 240,000 employees that is responsible for USA border and airport security, immigration policy, disaster response, refugee admissions and other matters.
Kelly brought her to the White House as his deputy when Trump named him chief of staff in July to replace Reince Priebus after only six months on the job.
At the White House, however, as Kelly's enforcer, Nielsen quickly emerged as a controversial presence.
Neilsen is an expert in homeland and national security policy.
"She would be the first person to run the department who has actually worked there", one person close to the Trump administration told Politico. Duke recently got into some controversy when she said that the hurricane response effort in Puerto Rico was a "good news story". "I think her no-nonsense, business-like manner is what earned the confidence, first of General Kelly, and now the President". Increased border security and a possible overhaul of the immigration system remain top campaign promises Trump has yet to fulfill, including his trademark wall on the border with Mexico.