Donald Trump once left Prime Minister Narendra Modi flabbergasted after he told him that India and China didn’t share a border, revealing the US President’s “woefully” poor knowledge of geography, according to a new book authored by two Pulitzer Prize-winning American journalists.

The 417-page book, ”A Very Stable Genius”, written by Philip Rucker and Carol D Leonnig, detailed similar vivid incidents from Trump’s tumultuous first three years as President, the Washington Post reported on Wednesday.

The businessman-turned-politician won the US presidential election in 2016 and assumed the position on January 20, 2017.

The book claimed during one of his meetings with PM Modi, Trump told him, “It’s not like you’ve got China on your border.”

However, the Washington Post report did not mention the year in which President Trump made this gaffe.

After Trump bungles his India-China geography, the authors, both Post reporters, claimed that “Modi’s eyes bulged out in surprise” and his “expression gradually shifted, from shock and concern to resignation”.

The two reporters were part of the team that won a 2018 Pulitzer Prize for its reporting on Trump and Russia.

The book quoted a Trump aide as saying that PM Modi probably “left that meeting and said, ‘This is not a serious man. I cannot count on this man as a partner'”.

“After the meeting”, the aide told the authors, “the Indians took a step back in their diplomatic relations with the United States.”

India and China have an unresolved border dispute that covers the 3,488 km Line of Actual Control (LAC).

PM Modi and Trump, who have developed a personal rapport, met four times in 2019, including their joint appearance at the historic ”Howdy Modi!” event in Houston. They spoke over the phone at least twice last year.