The WTA, the principal body that runs women's professional tennis, on Wednesday demanded a private meeting with Peng Shuai before any potential return of the circuit to China.
"We have received confirmation that Peng is safe and comfortable, but we have not yet met with her personally," the WTA said in a statement.
"As we would do with any of our players globally, we have called for a formal investigation into the allegations by the appropriate authorities and an opportunity for the WTA to meet with Peng - privately - to discuss her situation."
The former doubles world number one has not been seen outside China since first making, and then withdrawing, accusations of sexual assault against a high-ranking official.
Peng had alleged in a social media post that former Chinese vice-premier Zhang Gaoli forced her into sex during a years-long relationship, but has since twice denied she accused anyone of sexual assault and described the situation as a "huge misunderstanding".
"We continue to hold firm on our position and our thoughts remain with Peng Shuai and the WTA continues to work towards a resolution," the WTA said.
"While we have always indicated we are hopeful we will be in a position to again operate WTA events in the region, we will not compromise our founding principles in order to do so.
"There has not been any change in the WTA position on a return to China and we have only confirmed our 2023 calendar through US Open.
"A return to the region will require a resolution to the Peng Shuai situation in which Peng took a bold step in publicly coming forth with the accusation that she was sexually assaulted by a senior Chinese government leader."