If Donald Trump were president, the US would have no representative in attendance at the current G20 Summit in Hangzhou. The Republican nominee reportedly said he would have immediately turned around and flown back to the US after a recent bust-up between officials in China when Air Force One landed with President Obama.

As US and Chinese officials argued loudly on the tarmac, apparently over access to the event by American journalists, Obama was forced to exit via a secondary set of back stairs on the plane rather than down a front stairway to a red-carpet welcome.

While Obama has urged the press and public not to "over crank" the confrontation, Trump was seemingly incensed by the incident.

"They won't even give him stairs, proper stairs to get out of the airplane. You see that? They have pictures of other leaders who are . . . coming down with a beautiful red carpet. And Obama is coming down a metal staircase," a furious Trump said at a meeting with labour leaders in Ohio, the Washington Post reported.

"I've got to tell you, if that were me, I would say, 'You know what, folks, I respect you a lot but close the doors, let's get out of here,'" he added. "It's a sign of such disrespect."

The Clinton campaign jumped on the comments to demonstrate that Trump "lacks the temperament" to be president because he takes offence far too easily — and retaliates.

"Temperament Update: Trump would leave G20 meeting because the staircase offended him," tweeted campaign spokesman Jesse Ferguson.

Trump said in his talk that he "guaranteed it was built in China; it wasn't built here, okay?" The stairs in question, part of Air Force One, were, in fact, made in America.

Trump has complained about other tarmacs incidents, including in Cuba and in Saudi Arabia, where he believes Obama was not afforded the proper "respect" because leaders did not meet him. He called them incidents "without precedent."

In fact, heads of state have not greeted American presidents on "numerous occasions" in the past, according to the Washington Post. And, the newspaper said, an entourage of top government officials greeted Obama at both Cuba and Saudi Arabia.