Donald J. Trump is known rather colloquially here in the States as the “Liar in Chief.”

I have no idea what they call Kim Jong Un in his country, North Korea. Certainly nothing out loud, given the junior despot’s propensity for offing those who speak — or even think — ill of him.

This much apparently has been established about Kim: He’s a liar. Maybe he’s even more adept at lying than Donald Trump, not that the president is any good at lying.

Kim has made plenty of promises. And broken them. That makes him a liar. He comes from good lying stock, given what his father — Kim Jong Il — promised in 1994: He’d get rid of nuclear weapons; the elder Kim didn’t do what he said he would do.

As for Trump, well, his lying has become legendary: He said he tracked down evidence that Barack Obama was born in Kenya and not in Hawaii; he did nothing of the kind. He said he witnessed “thousands of Muslims” cheering the collapse of the Twin Towers on 9/11; he lied there. Trump said President Obama ordered the bugging of his campaign offices in Trump Tower; another lie.

He lies constantly. The question now becomes whether he knows he’s lying, whether he thinks he’s telling the truth or whether he knows that we know he’s lying, but doesn’t give a damn.

Trump and Kim have looked each other in the eye. Trump made more promises than Kim did, or so it appears. How does Kim believe the president who I am sure he knows is the pathological liar he has proven to be? For that matter, how does Trump trust Kim to keep his own word, given that he no doubt knows about Kim’s behavior?

I am fond of referring to a “liar’s contest” involving two men who are prone to telling tall tales.

Something tells me this newfound Donald Trump/Kim Jong Un “friendship” is built on a body of lies.