The welfare ministry and the Social Insurance Agency have launched a task force to help resolve the problem of unpaid national pension premiums in a bid to restore trust in the system, government officials said Monday.

The task force, headed by Chikara Sakaguchi, minister of health, labor and welfare, is expected to work on measures to improve premium collections, including compulsory collections, the officials said, noting legal efforts may be made to seize the assets of wealthy individuals who refuse to pay.

In the fiscal year that ended March 31, those who did not pay premiums for the "kokumin nenkin" national pension program, designed mainly for the self-employed, accounted for 37.2 percent of the total members, up from 29.1 percent the previous year.

The task force hopes to reduce the ratio to 20 percent within five years, the officials said.

At the day's meeting of the task force, Sakaguchi said he wants the public to realize that the national pension system exists to provide help on a mutual basis, according to the officials.

The officials said there are eight prefectures where the premium collection ratio is particularly poor. They are Aomori, Tokyo, Osaka, Hyogo, Fukuoka, Miyazaki, Nagasaki and Okinawa.

The task force plans to send Social Insurance Agency officials to regional offices of the eight prefectures to encourage them to strengthen their efforts to collect the national pension premiums.