Popovic was appointed in 2024 to replace Graham Arnold, who is now the coach of Iraq and also at the World Cup.
In his 18 matches in charge, he has won 10, drawn four and lost four.
"I'm delighted that I will continue to coach the Socceroos through to the Asian Cup," he said from California, where Australia are preparing for their opening Group D game on Saturday in Vancouver.
"From the moment I took over, I have tried to factor in the long-term interests of the Socceroos while ensuring that we achieve the short-term results, which in the first instance was qualifying for the World Cup."
The Asian Cup is due to be held in Saudi Arabia from January 7 to February 5.
"Securing Tony's contract extension on the eve of the World Cup is a fantastic outcome," said Football Australia chief Martin Kugeler.
"While the immediate focus is on the World Cup, this extension provides clarity and enables Football Australia to plan with absolute confidence for the period following the tournament, leading into the Asian Cup."
Australia, who are at their sixth successive World Cup, are also grouped with co-hosts the United States and Paraguay.
