'I love both events so it was a difficult decision but there are still significant risks involved due to COVID-19 and I don't feel comfortable putting my team and I in that position.'
World number one Ash Barty will skip the US Open and the tournament preceding it in New York due to concerns over the coronavirus pandemic.
"My team and I have decided that we won't be travelling to the US for the Western and Southern Open and the US Open this year," the Australian said in a statement issued by her manager on Thursday.
"I love both events so it was a difficult decision but there are still significant risks involved due to COVID-19 and I don't feel comfortable putting my team and I in that position.
"I wish the USTA all the best for the tournaments and look forward to being back in the US next year."
The Western and Southern Open, which is held annually in Cincinnati, has been moved to New York this year and is set to start in mid-August.
The US Open kicks off on August 31 and will be held in its usual home in Flushing Meadows, Queens, but will be played without fans in attendance to limit the spread of the virus.
The reigning French Open champion will decide later whether to defend her title at Roland Garros starting in late September.
"I will make my decision on the French Open and the surrounding WTA European tournaments in the coming weeks," she said.
World number one Novak Djokovic and 23-times Grand Slam champion Serena Williams are among players expected to compete at the US Open despite concerns about undergoing mandatory quarantine when travelling to Europe, which would have them miss tournaments in Madrid and Rome ahead of the French Open.
Deaths from COVID-19 surpassed 150,000 in the United States on Wednesday, more than any other country and nearly a quarter of the world's total, according to a Reuters tally.
Osaka will play in US Open, says management team
Naomi Osaka will play in next month's US Open in New York, the 2018 champion's management team has told Reuters.
Several media reports had said she had not registered for the tournament and had decided to skip the event, which kicks off on August 31 and will be played under strict bio-security protocols due to the COVID-19 pandemic.
However, the 22-year-old's management team told Reuters via email that the reports were wide of the mark and that she would be participating at Flushing Meadows.
Osaka would also be playing in the Western and Southern Open, which is held annually in Cincinnati but has been moved to New York this year and is set to start in mid-August.
Japan's Osaka, who is based in the United States, last played competitive tennis in early February during Fed Cup qualifiers against Spain.