An entity that will oversee the calculation of the new rates will be created soon, Amamiya said in a speech.
As a first step, the entity will release from around spring this year "reference rates" for the new benchmark that will not be used for actual transactions, he said.
It will then release formal rates that can be used for actual transactions around mid-2021, Amamiya added.
"Interest rate benchmarks are among critical infrastructure for players engaging in financial and economic activity," Amamiya said at a seminar organised by Jiji news agency.
Libor, a widely used benchmark for financial transactions, was discredited after the 2008 financial crisis when authorities in the United States and Britain found traders had manipulated it to make a profit.
The Federal Reserve, the Bank of England and other major central banks now publish overnight rates for use instead of Libor. The BOJ hopes to follow suit, as such "risk-free" rates are seen as harder to manipulate as they are based on actual market transactions rather than quotes.
Regulators are piling pressure on banks to use the new rates by the end of 2021, though progress has been slow including in Japan.
(Reporting by Leika Kihara; Editing by Jacqueline Wong)