Bank of Japan Governor Kazuo Ueda said that while Japan's inflation rate has reached policymakers' target, how long it can stay there remains uncertain, suggesting that 2% inflation has not yet fully taken hold in Japanese society.

Speaking during a question-and-answer session after a speech at the IMF on Friday, Ueda said: "The underlying inflation rate is 2%, and our goal is to keep it at that level." He said: "I think we are now in an equilibrium state. As for whether we can maintain this equilibrium for a very long time into the future, we do not know."

In a conversation with IMF Managing Director Kristalina Georgieva, Ueda did not give any specific guidance on the central bank's willingness to raise interest rates further.

When asked how various parties reacted after the inflation target was achieved, Ueda said: "I would say that 2% inflation has not yet fully become the social norm. That is the general view both inside and outside the central bank. Indeed, we have reached an important milestone, but there is still a lot to do. This means it is necessary to keep inflation at this level for many years to come through appropriate adjustments to monetary policy."

Ueda earlier also delivered a speech on the history of Japan's current account surplus and noted some signs of a renewed rise in corporate risk appetite.

He said: "Recently, the growth rate of bank lending has exceeded 5%, the fastest in 30 years. With the return of moderate inflation, corporate risk appetite appears to be warming again."