Diederich lives in Miami but has had a near lifelong connection with Haiti in the Caribbean, which ranks alongside New Zealand as his favourite place.
An old boy of St Pat's in Wellington he studied in England in the years immediately after World War II and having served in the Pacific.
Four years after the end of the war, Diederich was on a sea voyage with friends and called at Haiti.
He fell in love with the country and stayed to found and edit a weekly English newspaper there.
The Heritage Boutique Martinborough Hotel is launching an entertaining new literary event series and will host the luncheon in Diederich's honour on February 25.
At the luncheon, presented in conjunction with the National Press Club, Diederich will present his new book Seeds of Fiction about his long friendship with Greene.
It includes Diederich's account of accompanying Greene on his tour of the Haiti/Dominican Republic border. It was this journey which Greene commemorated in his book The Comedians, later to be made into a film.
Diederich was one of the last people to visit Greene in his Mediterranean apartment shortly before the British author died. He had introduced Greene to Fidel Castro and to fellow Caribbean dictator Omar Torrijos, a friendship enshrined in Greene's book Getting to Know The General.
Diederich was formerly Time-life's bureau chief for Central America. He is the author of many books on the region's dictators including Somoza, Duvalier, Trujillo, Torrijos and Castro, all of whom he knew personally.
Tickets to the two-hour literary luncheon cost $65 for a two-course meal and selected wine. Copies of Diederich's books will be available to be bought and signed on the day.
Tickets are limited and bookings close on February 12.