Melbourne - Tennis superstar Serena Williams on Tuesday said she was concerned about the fight for equality as she used Martin Luther King Day to spread the message at the Australian Open.
The 22-time Grand Slam winner wore a T-shirt emblazoned with the word "Equality" as she spoke to media after sweeping into the second round of the Grand Slam tournament.
"With today being Martin Luther King Day, it's important to spread the message of equality, which is something he talked about a lot and he tried to spread a lot - equality and rights for everyone," said Williams.
She added that many athletes "really want to be a part of this movement".
"And we really just want to speak up about things that we believe in and talk about equality," she said.
She refused to comment on US president-elect Donald Trump, who met King's eldest son in New York on the US holiday honouring the slain civil rights icon.
The meeting took place amid a brewing spat with one of King's close collaborators, Congressman John Lewis, who has vowed to boycott Trump's inauguration ceremony this week.
Williams, arguably one of the greatest athletes ever, has been outspoken on women's rights and gender and race issues in recent times.
Asked if she was concerned about the future of equality in the United States, the 35-year-old replied: "I think it's a concern for just everyone in general.
"We want to make sure we always continue to move forward and always have the opportunity to have equal rights for all.
"We don't want to stop that forward movement. It's just always great to raise awareness for it."
Pressed on whether she feared what might happen to equal rights under the Trump administration, she said: "I don't talk - I don't have any comments on that."
Lewis, a high-profile lawmaker, last week questioned the legitimacy of the US presidential election, citing what he dubbed Russian interference, and vowed to boycott the inauguration.
In response, Trump hit back at a man widely seen as an American hero who was beaten while leading the Alabama civil rights march known as "Bloody Sunday".
"All talk, talk, talk - no action or results. Sad," he tweeted.