The 36-year-old was eight weeks pregnant last year when she triumphed for a seventh time at Melbourne Park to claim an Open-era record 23rd Grand Slam title.
"My coach and team always said "only go to tournaments when you are prepared to go all the way", Xinhua news agency quoted Williams as saying. She's decided that she isn't ready to perform at a professional level after giving birth in September. "With that being said, and even though I am disappointed about it, I've decided not to compete in the Australian Open this year", she said.
"Serena transcends the sport in the way she approaches all aspects of her life".
Failed missile test hits North Korean town
However, the cold relationship between South Korea and the North showed signs of thawing in the beginning of 2018. Earlier in the month North Korea had threatened the U.S. with "nuclear justice" and "thermonuclear war".
After 11 months off, Williams was defeated 10-5 in a supertiebreaker after she split the first two sets with French Open champion Jelena Ostapenko in an exhibition match at the Mubadala World Tennis Championship.
Meanwhile, Australian Open tournament director Craig Tiley expressed his admiration on Serena's efforts to return to the game she likes. The 12-time Grand Slam victor will also play the Tie Break Tens at Margaret Court Arena at Melbourne Park on January 10 in the evening, joining Rafael Nadal, Stan Wawrinka, Nick Kyrgios and Lleyton Hewitt in the field.
Novak Djokovic is slated to play two exhibition events before taking a final call on his participating at the Australian Open which begins from January 15.