WATCH LIVE: House Dems grill DHS chief Kirstjen Nielsen on false statements about deaths of migrant kids
DHS photo of Kirstjen Nielsen by Jetta Disco.

Homeland Security Secretary Kirstjen Nielsen will face tough questions from House Democrats about her role in the Trump administration's family separation policy at the border.

The DHS chief will testify Wednesday morning before the House Homeland Security Committee led by Rep. Bennie Thompson (D-MS), starting at 10 a.m.

Democrats are expected to ask Nielsen about President Donald Trump's emergency declaration, his proposed border wall and the deaths of migrant children in U.S. custody, according to congressional aides.

Committee staffers also warned that Nielsen should expect to be grilled about her false or misleading statements to Congress about the deaths of migrant children taken from their parents at the border.

“Secretary Nielsen would be wise to finally tell the truth about the Trump administration’s grotesque family separation policy,” one senior staffer told The Daily Beast. “If she refuses to do so, Democrats on the committee won’t hesitate to call her a liar.”