Two-time U.S. Open champion Naomi Osaka is hoping a return to the hard courts of Flushing Meadows will mark a turning point in what has been an erratic tennis comeback.

"I was watching in the stands last year, and I promised myself this was going to be the tournament where I do the best," said Osaka, who returned to tennis late last year after taking 15 months off for the birth of her daughter Shai.

"Hopefully here or Japan or during the Asian swing — that's kind of where I put all my energy. I guess we'll see what happens," added Osaka as she spoke to reporters on Saturday, two days before the start of the year's final Grand Slam.