President-elect Donald Trump's choice for Homeland Security secretary portrayed illegal immigration as an "invasion" and the U.S.-Mexico border as a "war zone" during a U.S. Senate confirmation on Friday where she pledged to back Trump's hard line on immigration.

Noem vowed Friday to immediately halt the controversial mobile app that lets migrants register to enter the US.

Alabama Senator Katie Britt, chair of Senate Homeland Security Appropriations, believes Noem is committed to securing the U.S.-Mexico border after successful confirmation vote Saturday.

Gov. Larry Rhoden received Kristi Noem's official resignation as South Dakota governor on Saturday as she joined the Trump administration.

The Senate confirmed Kristi Noem as homeland security secretary on Saturday by a 59-34 vote, putting the former South Dakota governor in charge of a sprawling agency that is essential to national security and President Donald Trump's plans to clamp down on illegal immigration.

The role is key to Trump’s plans for his second term after pledging to deport millions of undocumented immigrants and impose a crackdown at the southern border.

Noem will now lead a federal department tasked with enforcing Trump’s hardline immigration policies, despite her lack of experience with homeland security issues.

The two term South Dakota Gov. was tapped by Trump in Nov. and will be key in enacting the new president's mass deportation plan.

Noem and committee Republicans focused on the border while Democrats asked about foreign and home-grown terrorism during a cordial hearing.

The department that the South Dakota governor seeks to lead will be critical to fulfilling the incoming administration’s promises to quickly crack down on immigration.

Kristi Noem, President-elect Donald Trump's nominee to lead the Department of Homeland Security (DHS), vowed at her Senate confirmation hearing to lead a crackdown on immigration by securing the "war zone" at the US-Mexico border and deporting unauthorised migrants.