Biwott, the fastest man in the field, won his first major marathon on the New York streets last year, but must erase any doubts about his fitness after dropping out of the Rio Olympic marathon mid-race in August.
"This will be my chance to prove I am still a worthy bet in running," the 30-year-old London Marathon runner-up told reporters in Nairobi.
Keitany bids to become the first woman in three decades to win New York three consecutive times. Nine-time winner Grete Waitz was the last, her streak of five in a row ending in 1986.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
But the 34-year-old Keitany, an overwhelming favourite, also is looking to remind Kenyan selectors once again of their mistake in not picking her for the Rio Olympics.
"I thought I earned a ticket to Rio," Keitany said on Friday. "So let me just focus on the marathon for New York and come to defend my title."
Ethiopian Aselefech Mergia, the 2015 New York City runner-up, should again challenge Keitany with the former's compatriot Buzunesh Deba and Kenyan Joyce Chepkirui also in the mix.
U.S. Olympic triathlon gold medallist Gwen Jorgensen and Molly Huddle, the American record holder at 10,000 metres, will make their marathon debuts in the women's race.
Biwott's biggest threats among the 50,000 runners expected to participate in the race through New York City's five boroughs are likely to come from fellow Africans Ghirmay Ghebreslassie of Eritrea, Ethiopian Lelisa Desisa and Kenyan Lucas Rotich.
Ghebreslassie finished fourth in Rio and at the London Marathon after becoming the youngest ever world marathon champion last year at age 19.
Desisa, 26, has twice won the Boston Marathon and finished second there this year. He placed third in New York last year.
The 26-year-old Rotich's credentials are not as impressive, but he continues to improve on the roads and is one of only five men in the field who have broken two hours and eight minutes for the marathon.
One other is three-time Olympian Dathan Ritzenhein, who with a personal best of 2:07.47 is the top hope for the United States, which last won the race in 2009.
(Reporting by Gene Cherry in Salvo, North Carolina; Editing by Frank Pingue)
