Donald Trump's incoming U.S. presidential administration plans to intensify immigration enforcement nationwide soon after he takes office on Monday, a person with knowledge of the plans said.

The size of the planned operation is unclear, but it would be the opening step in the president-elect’s goal of overseeing the largest deportation program in history.

Presidents from both parties have raided businesses alleged to have hired people who are in the country without legal status. Here’s what we know about how they may work under a second Trump administration.