John Kelly, who had been serving as the president's secretary of homeland security, takes a key role at the White House after a week of staff turmoil and infighting.
Just days after the Department of Homeland Security detailed how it will implement President Trump's policies, Mexican officials warned Thursday they would not accept "measures imposed unilaterally."
Of the 680 people arrested, around three-quarters had convictions, Homeland Secretary John Kelly said. Advocacy groups report that the raids also swept up people with no criminal record at all.