The government approved a bill Friday to raise its contribution to the national pension scheme to one-half from one-third in fiscal 2009, which begins April 1.
The state usually provides a third of the funds needed to operate the government-run pension scheme, which distributes benefit payments to all pensioners.
The remainder is mainly covered by pension premiums paid by future pensioners.
The bill, which has been endorsed by the Cabinet, would revise the national pension scheme law to raise that ratio to half.
The government is also considering tapping reserve funds from a special account buried in the government's fiscal investment and loan program (also known as "zaito") to raise the ¥2.5 trillion or so it estimates will be needed to finance the higher burden in fiscal 2009 and fiscal 2010, officials said.
From fiscal 2011 onward, however, the government has no idea how the contribution will would be maintained.