Ukraine's Marta Kostyuk refuses handshake with Belarusian Victoria Azarenka after U.S. Open defeat

Kostyuk explained her decision to ESPN afterwards.

"Kostyuk, who has been vocal about her unhappiness about Russian and Belarusian players' silence on the tour, said it was not appropriate to shake hands with Azarenka at the news conference after the match," ESPN's Aishwarya Kumar wrote.

"It was my choice -- I don't feel like I don't know any single person who condemned the war publicly, and the actions of their government, so I don't feel like I can support this," Kostyuk said. "Don't get me wrong, she's a great competitor. But, it has nothing to do with her being a human being."

According to Kumar, Ukranian player Dayana Yastremska also refused to shake hands with Azarenka after a match at the Citi Open in August. Yastremska fled Ukraine with her younger sister days after the Russian invasion began in February.

Belarus has been hit with heavy sanctions by the United States for its "support" and "facilitation" of the invasion.

"Kostyuk said that Azarenka has not reached out to her to have a conversation since the beginning of the war. Kostyuk said given Azarenka's reach both in Belarus and as a part of the WTA's Players' Council, she should use her voice to condemn the war," Kumar wrote. "Kostyuk also said she had texted Azarenka Wednesday after her practice session to 'warn her' that she will not shake hands with her after the match today. Kostyuk also said she wanted to have a broader conversation with Azarenka on the war and hear her thoughts on where the Belarusian stood. Kostyuk said Azarenka responded that she was not on site, and so they did not have the conversation."