[Regulator]

and politely

Don't be polite. It's taken as a sign of weakness.

[Pablo64]

Not if you’re firm about it. You can be very adamant and remain polite. People will understand by your facial expressions and body language that there is no weakness behind the polite instruction.

[Marine Inspector]

I’ve been doing immigration law enforcement in Arizona for the past 10 years and I’m always polite. The aliens that I have removed from the US have never mistaken my politeness with weakness.