The menu for Trump's midday meal with his host in Hanoi, Vietnamese Prime Minister Nguyen Xuan Phuc, spreads to five courses covering the varied delights of Vietnam's cuisine.

According to the White House, things start light: "Fresh shredded green mango salad with scallops, mint leaves and cashew nuts served in a sweet vinaigrette dressing."

If that doesn't do much for the famously heavy eating US president, he won't have long to wait.

Course two features deep-fried spring rolls, course three stars king crab meat and spinach in a light seafood-based broth, and course four is guaranteed to get the presidential seal of approval:

"Grilled cod fish 'cha ca'; roasted Wagyu beef medallions with foie gras and a semi-sweet fermented black rice sauce; sauteed 'su su' vegetables with garlic (crispy green chayote stems and leaves); steamed sticky glutinous rice with shrimp wrapped in a lotus leaf."

If he has any room left, Trump will be treated to dessert "consisting of lotus seeds, longans, and white wood-ear mushrooms served warm and in a light sugary syrup".

Then he can wonder what -- apart from trying to persuade Kim to give up North Korea's nuclear weapons -- will be for dinner.

During a previous visit to Vietnam, shark's fin was on an early version of a menu due to be served to Trump but was reportedly left off the table after causing a stir online.