Less than 600 people crossed illegally into the U.S. from Mexico on Sunday – a stunningly low number since President Donald Trump took office.

President-elect Donald Trump hasn’t even been sworn in yet, but his promises of an immediate border crackdown are already stoking fear among migrants, who have started thinking twice before illegally entering the US.

The number of immigrants arrested for entering the United States from Mexico illegally has been cut in half since October, marking a stark decline since the election and the early days of President Donald Trump’s second term.