The government might increase its share of the public pension burden in phases, not all at once next year as promised, Prime Minister Junichiro Koizumi said Tuesday.
The government had promised to raise its share of the burden to half from one-third in fiscal 2004.
The increase will cost 2.7 trillion yen, a huge outlay for the seriously debt-ridden government.
"I don't think we have to raise the burden to half in only one year," Koizumi told a news conference to officially publish the Liberal Democratic Party's campaign pledges, which were unveiled last week.
The increase is widely expected to lead to a hike in the consumption tax rate, a political taboo for parties as they gear up for the Nov. 9 general election of the House of Representatives.
The government and the LDP have said they will decide by the end of the year how to finance their promise to take on more of the pension burden. This is an apparent attempt to avoid turning it into a policy issue before the Nov. 9 election.
Later in the day, Chief Cabinet Secretary Yasuo Fukuda told reporters that Koizumi was apparently stating his own idea on the matter. Fukuda denied that Koizumi's remarks reflected official government policy.
"We haven't started boiling down specific ideas yet," Fukuda told a news conference.