Bemused and amused people in several US cities have encountered naked Donald Trump statues that were cheekily installed in public places this week.

The life-size statues appeared in New York, San Francisco, Los Angeles, Seattle and Cleveland, NBC reports.

Pictures and clips of the statues show they are a caricature of the presidential candidate, with exaggerated features such as veins and a masonic ring on one of the statue's fingers.

There is also one particular missing element - a small plaque on each of the sculptures gives the project title as 'The Emperor Has No Balls'.

The INDECLINE protest group has said it was responsible for the stunt.

In a statement quoted by NBC, the group said they hope Trump "is never installed in the most powerful political and military position in the world".

Local officials have been removing the statues, with the New York parks department showing a sense of humour about the matter in their statement to journalists:

NYC parks department on naked Trump statue: "NYC Parks stands firmly against any unpermitted erection in city parks, no matter how small.”

— Josh Dawsey (@jdawsey1) August 18, 2016

Meanwhile, the real Donald Trump has expressed 'regret' for sometimes saying the 'wrong thing' on the campaign trail.