The White House said no official delegation would be sent to the Games because of concerns about China's human rights record.
But it said US athletes could attend and would have the government's full support.
China has previously said it will take "resolute countermeasures" in the event of a boycott.
US President Joe Biden said last month that he was weighing up a diplomatic boycott of the event.
White House press secretary Jen Psaki confirmed the boycott on Monday, saying that the administration would not contribute to the "fanfare" of the Olympics.
"US diplomatic or official representation would treat these games as business as usual in the face of the PRC's [People's Republic of China] egregious human rights abuses and atrocities in Xinjiang," she said. "We simply can't do that."