Ashleigh Barty says she believes she can still improve further after topping the world rankings.

The Australian began the year as the world number 15 and claimed top spot in June after breaking her Grand Slam duck by landing the French Open.

Barty will look to land a second major at the US Open later this year and is 10.00 to take the title in New York. The 23-year-old admits she has been surprised by her success in 2019 but feels she can still raise her game further.

“It’s been just the most incredible journey for us and my team – it’s happened very quickly,” Barty said of her 2019 campaign so far to reporters in Brisbane.

“We had plans and goals for this year to try and crack into that top 10 and that was kind of the next level for me and then to be able to get to world number one so quickly has been incredible.

“We worked incredibly hard for it and enjoyed every single minute of it and now the challenge for us is to keep improving and try and stay there as long as we can.”

She added: “I’m more driven and more and more hungry than ever to try and get better – there are still so many players out there that I want to beat.”

Serena Williams is the 5.50 favourite to win the US Open outright and Wimbledon winner Simona Halep is available at 6.50.