Cyber expert tapped to lead DHS

President Donald Trump tapped White House Chief of Staff John Kelly's top aide to assume his former role as secretary of the Department of Homeland Security, according to multiple media reports.

Kirstjen Nielsen, who served as Kelly's chief of staff during his brief tenure at DHS, followed Kelly to the White House. Trump formally announced Sept. 6 she would serve in the role of principal deputy chief of staff.

The cabinet post has remained vacant since Kelly departed DHS in July.

Nielsen, 45, has a background in national security policy, cybersecurity, critical infrastructure resiliency, as well as emergency preparedness and response.

Under the Bush administration, Nielsen served as special assistant to the president for prevention, preparedness and response on the White House Homeland Security Council.

Before joining the Bush White House, she created and oversaw the Offices of Legislative Policy and Government Affairs within the Transportation Security Administration, where she worked on policy surrounding background checks, prescreening and other transportation security measures.

In the private sector, she has worked for the law firm Haynes and Boone LLP and as general counsel and president of the Homeland Security and Private Sector Preparedness practice at Civitas Group. She also founded Sunesis Consulting LLC, where she advised government and private-sector officials on security strategies and policies with a focus on critical infrastructure.

In a 2016 article, Nielsen warned that "the evolving nature of cyber risk … is not fully understood."

Before joining the Trump administration, Nielsen was a senior fellow at George Washington University's Center for Cyber and Homeland Security.

On Capitol Hill, key committee leaders praised Nielsen's experience.

"Kirstjen thoroughly understands the inner workings of the Department having served there twice and has extensive background in national security policy decision-making with her time in the White House. Both will prove very beneficial as she prepares to lead a diverse organization with such critical missions," said Rep. Michael McCaul (R-Texas), chairman of the House Homeland Security Committee. McCaul was considered in the running for the top DHS job himself.

Sen. Ron Johnson (R-Wisc.), chairman of the Senate Homeland Security and Government Affairs Committee, said that the Nielsen's "long history of service with the Department, her cybersecurity experience and her tenure serving with General John Kelly would serve her well as the next Secretary of the Department of Homeland Security." He pledged to expedite her confirmation before his committee.