Prize is open only to British and Commonwealth citizens and Indian-born Desai has yet to apply for a US passport, although she has lived in New York for 20 years.
"George Bush won once and he won the second time and I couldn't bring myself to (apply)," Desai said late last month in an interview in Toronto as she voiced her disapproval of the president's foreign policy.
"So I really owe George Bush my Booker, in an odd way. It's really very funny."
Desai, 35, became the youngest woman to capture the £50,000 ($95,000) prize last month with her sweeping novel The Inheritance of Loss. The book's narrative ranges from undocumented workers in New York to political violence in the foothills of the Himalayas during the 1980s.
The novelist divides her time between New York and New Delhi, and while she finds travelling difficult on an Indian passport, she said it helped her maintain an essential contact with her roots while penning her prize-winning book.
"I couldn't have written this book without being interested (in India), I felt very Indian while writing it," she said.
"With politics in the United States, my immediate thought is how is this going to affect India or the Third World, who are they letting into the country, who they happen to be bombing."
But Desai is quick to point out that her book deals with an underclass that is exploited in rich and poor countries alike.
One character is a cook who has to feed his master's dog better food than he gets himself, while his migrant son is also a cook, in New York. Both sleep in the kitchens where they work long hours for a pittance.
"The locations may seem very far apart, but they are more closely linked than we think," she said.
Kiran Desai succeeded in winning the Booker Prize where her mother, Anita Desai, also a writer, had failed after being a finalist three times.
"Writing is always hard. I spent seven years working on it and it was hard to get this novel published, whoever my mother was," she said.
"Her help was huge in terms of having someone to understand what you are going through. She was the only person who stood by me this whole time," she added.