Belarusian star Victoria Azarenka, a former world number one and two-time Grand Slam title winner, withdrew from the Toronto WTA event on Sunday, claiming she had been refused a visa to enter Canada.

"I have had to withdraw due to my visa not being approved," the 33-year-old wrote on Twitter.

"It's truly disappointing. It's very sad to miss one one of my favourite tournaments. I love to play in Canada with great fans and a place where I made many friends over the years."

Along with other Belarusian and Russian players, Azarenka was banned from this year's Wimbledon due to the invasion of Ukraine.

Players from the two countries are allowed to compete at other tournaments but not under the name or flag of their countries.

Azarenka said she hoped to return to action in Cincinnati from August 13, one of the last events before the US Open gets underway in New York on August 29.

At the Toronto WTA tournament, which starts on Monday, Azarenka had been drawn to face Olympic champion Belinda Bencic in the first round.