The Women's National Basketball Players Association said in a statement its members had voted in favor of authorising the union's leadership to call a strike if needed.
"The players have spoken," the WNBPA said in a statement. "Through a decisive vote with historic participation, our membership has authorised the WNBPA's executive committee to call a strike when necessary."
The statement accused the WNBA and team owners of "a resistance to change and a recommitment to the draconian provisions that have unfairly restricted players for nearly three decades."
The WNBA said 93% of eligible union members had participated in the vote, with 98% voting in favor of a strike if deemed necessary.
"Let it be known. The players remain united, resolute, and prepared to fight for their value and their future," the union added.
WNBA players are seeking a greater share of league revenues and improved benefits and working conditions. The ongoing talks have a deadline of January 9.
The Women's National Basketball Association said it "strongly disagreed" with the union's characterisation of ongoing labor talks.
"We are aware that the players have voted to authorise the WNBPA executive committee to call a strike if the executive committee decides to take that step in the future," a WNBA statement said.
"It is difficult to understand claims that the league is resistant to change, particularly given that we are proposing numerous CBA modifications including significant immediate salary increases and a new uncapped revenue-sharing model."