MELBOURNE, Jan 19 (Reuters) - Differences in host countries" laws might make it too hard to impose a COVID-19 vaccine mandate on all the women on the professional tennis circuit, tour players" council member Victoria Azarenka said on Wednesday. Mandates have been proposed in some quarters after the issue of vaccinations dominated the tennis headlines for a week before Novak Djokovic was deported from Australia on Sunday evening. read more Azarenka, a former world number one, said she believed getting vaccinated was the socially responsible thing to do, and that the WTA was right to encourage it, but that a mandate was problematic. "I believe in science. I believe in getting vaccinated. That"s what I did for myself," she told reporters after reaching the third round of the Australian Open with a 6-1 6-2 victory over Jil Teichmann. "As an entity, as an association of WTA, that is travelling globally, we still have to respect countries, different countries, different mandates, different legalities of the country. "Some countries will not allow mandates. I think to impose something legally on the WTA Tour can be a challenge." Spaniard Rafa Nadal, who recently recovered from COVID-19, said he would support any measure that made conditions safer. "We went through (biosecure) bubbles for two years, very challenging conditions," the 20-times major champion said. "If everybody"s vaccinated, we are allowed to improve our life on the tour, and most important our life outside of the tour." Djokovic and a handful of other unvaccinated players and officials arrived in Australia this month and last holding medical exemptions that were supposed to allow them to avoid a vaccination requirement for visitors. Azarenka said she thought the affair could have been prevented by having clearer rules. "As soon as there is a grey area in the rules, that gives a bit too much questions, and situations like this happen. "On certain things, I think a black-and-white approach is necessary." The WTA and the ATP did not immediately reply to requests for comment about vaccine mandates. Azarenka said discussions were continuing about replacement events after the WTA suspended tournaments in China because of concerns about the safety of former doubles number one Peng Shuai. read more "As an association, women"s association, I am proud that we are supporting our players. I think that kind of should go without saying," she said.