The 23-time grand slam winner did not feature in the tournament last year after the birth of daughter Alexis Olympia Ohanian Jr.

Williams has yet to win a major since returning to action — she lost to Angelique Kerber in the final at Wimbledon in July — while she has not been crowned singles champion at the US Open since 2014.

However, speaking to the media before the tournament, the American revealed having a child has not diluted her desire for success, in fact quite the opposite.

"I feel like everything is just different in terms of I'm living a different life, I'm playing the US Open as a mum. It's just new and it's fresh," Williams said.

"If anything, I have more fire in my belly. It's very hard to describe. It's very difficult to describe. I thought after having a child I would be more relaxed. I think I've said this before, but I'm not.

"I work just as hard, if not harder actually. I just feel like I take it just as serious, if not more. That's been really surprising for me."

The 36-year-old is seeded No.17 and, despite a tricky draw that sees her in the same section as world No.1 Simona Halep, is considered one of the favourites for the title.

Williams starts out against Poland's Magda Linette but is not even aware who she could face in the later rounds.

"That I would be the favourite at this point, almost a year after having a baby, is quite interesting," she said.

"You know, I don't know my draw, but I feel like — if I want to be the best — I'm going to have to start beating these people anyway."