The review, by Michiko Kakutani, appeared in the newspaper's online version overnight, ahead of the official release of the eagerly awaited "Harry Potter and the Deathly Hallows" at 0001 British Summer Time on Saturday or 2301 GMT on Friday night.
Bloomsbury, which publishes "Harry Potter" in Britain, and Scholastic, its U.S. publisher, spent millions of dollars trying to protect the contents of the novel until its official publication.
But copies of "Deathly Hallows," believed to include both fake and real versions, have surfaced on the Internet and this week some books were shipped to customers by a U.S. online retailer, prompting Scholastic to take legal action.
The seventh and final Harry Potter installment is expected to become the world's fastest selling book after months of hype and speculation about its contents, including what happens to the boy wizard and his friends at Hogwarts.
The New York Times review said its copy was purchased from a New York City store on Wednesday.
Bloomsbury called the review "very sad," adding that there was only one more day to wait until the official release in book stores around the world. Twelve million copies of the book have been printed for the U.S. market alone.
"We will be relying on the support of the media to allow the fans to read the book for themselves rather than having to see reviews that may have been based on fake postings on the Internet," said a spokeswoman.
She likened recent events in the United States to the Boston Tea Party, a protest by American colonists against Britain in 1773.
"But over here it is blockades as usual, with the embargo being enforced unflinchingly and without exception by all our customers," she said.
"We would like fans all over the world to be able to come to this book on July 21 to find out for themselves what's going to happen. It's only a few more hours to go."
In a generally positive review, writer Kakutani gives away some plot details, including how many characters die and what "deathly hallows" means, but refrains from answering the biggest questions of all.
"Ms. Rowling has fitted together the jigsaw-puzzle pieces of this long undertaking with Dickensian ingenuity and ardor," the review said.