The Bank of Japan rejects the idea that additional monetary stimulus is needed to prevent a recent decline in oil prices from pulling down inflation, according to sources familiar with the discussions.

For now, policymakers assess that while cheaper energy costs may weigh on consumer prices for a time, they ultimately will boost the economy, spurring inflation, said the sources, who asked not to be named because the discussions are not public.

Less agreement is found on how much capacity the central bank has to expand its buying of government debt, some of the sources said.