In an interview with BBC radio, the chancellor of the exchequer spoke of the need to provide Britons with "fiscal security" following Brexit.
Asked if that meant taxes would rise and spending cut, Osborne replied: "Yes, absolutely. But that decision will come under a new prime minister. It's obviously not possible while the Conservative Party is having a leadership contest."
Conservative Prime Minister David Cameron resigned in the wake of Thursday's shock referendum result. Both he and Osborne had been at the forefront of the Remain campaign to persuade the electorate to vote to keep Britain in the EU and avoid a recession.
"We are absolutely going to have to provide fiscal security to people, in other words we are going to have to show the country and the world that the country can live within its means," the chancellor added.
Osborne, long tipped to succeed Cameron, has meanwhile ruled himself out of the contest to replace the prime minister.
