The US Open seedings went to ranking, the United States Tennis Association confirmed, with Novak Djokovic and Serena Williams earning top billing at Flushing Meadows.

Williams finds herself at the top of the draw as she looks to win the calendar Grand Slam on home soil, while Djokovic can make it three-from-four in 2015 with a win in New York.

Roger Federer is seeded second, meaning any re-match with Djokovic after the Swiss won the Cincinnati final would be in the decider.

Simona Halep is Williams' potential final rival as the second seed in the women's draw.

Defending men's champion Marin Cilic is seeded ninth, which will mean he is in line to face a top-eight rival in the last 16.

Meanwhile, Williams is not only aiming for a sweep of the majors this season, but also a fifth in succession - having lifted the US Open title for the sixth time last year - and a fourth straight New York title.

The luckiest players among the seeds were Fabio Fognini and Anna Schmiedlova - the pair sneaking into the respective 32nd seedings and avoiding a potentially tough draw early.

The unlucky ones are Leonardo Mayer and Karin Knapp, the world number 33s on each of the ATP and WTA tours susceptible to being drawn against seeds when Friday's draw is completed.