President Donald Trump's administration has directed U.S. prosecutors to criminally probe state and local officials who resist immigration enforcement efforts, intensifying a sweeping crackdown that Trump launched the day he took office.

The threatening letters came from a nonprofit headed by Stephen Miller, who is expected to be Donald Trump's deputy chief of staff for policy.

State and local leaders across the country are bracing for a tidal wave of aggressive immigration policies and possible mass deportations that President Donald Trump has vowed to enact in the hours and days following his inauguration Monday.