"Remind me why we're doing this?" Donald Trump demands of his wife, Melania, who is casting a critical eye over the staff as they nervously set the Big Table in the State Dining Room at the White House, Washington DC.

"We better pack a few of my longest ties," Scott Morrison says to his wife Jenny as they fuss around the suitcases in the PM's dressing room at The Lodge, Canberra. "First impressions count."

Donald Trump has invited Scott Morrison to visit Washington DC. Credit:Alex Ellinghausen

"I mean, we should have it at my golf course over in New Jersey, at least," says the US President. "Trump National Golf Club. We could charge everyone. Lots. Every little bit helps. Tell 'em it's my Summer White House."

"How could we have ever imagined, Jenny, back when I was running Tourism Australia, that we would end up as the guests of the leader of the free world at the White House at an official dinner in our honour!" breathes the Prime Minister.