So it comes as little surprise that their competitive streak made a special appearance at today's high profile meet 'n' greet.
Eagle-eyed observers noted that the North Korean leader appeared to be wearing shoes with a lift, to give him a little extra height … which would better place him to eyeball Trump's tangerine chin.
Kim Jong-un made the bold choice to wear a pair of wide pants, presumably to hide his secret stacked heel.
Apparently the angle of his foot in photos from today's summit shows he is wearing shoes with special height-adding insoles.
Behold:
Chosun Ilbo does some investigative reporting on Kim Jong Un's shoes and finds the angle of his foot means he was wearing special height-adding insoles -- suggesting the height difference with Moon Jae-in was larger than it appeared last week,https://t.co/DXCQZgWPhapic.twitter.com/00kCLgCF6O
While the tweet above suggests Donald Trump is 6ft 3inches tall, it's been suggested that his reported height may be a sneaky move on the Don's part.
It's been reported that the US President may have slightly overstated his height so he doesn't register as obese on the BMI index (which calculates whether you're in a healthy weight range when factoring in height and weight).
People started asking questions after photos of the G7 leaders standing in a row showed Trump a fraction shorter than Canadian Prime Minister Justin Trudeau, who stands at 6'2".
But we've gone off topic. Let's get back to Kim Jong-un and his fancy trick shoes.
It seems he's been wearing these platform boots for a while and apparently opts for a 5cm lift.
While this is all well and good, the award for best powerplay in this whole exchange still goes to Kim Jong-un not for his footwear, but for kicking things off by having Trump photographed with a novelty-sized envelope that made his hands look like they belong to a baby.
Kim Jong Un to underling: I want you to go to the stationery cupboard and find the biggest freakin’ envelope you can find. We’re gonna make that guy’s hands look like a doll’s. pic.twitter.com/2IYgeJkNuq