The national poverty rate stood at 15.7 percent in 2006, according to first-ever figures released Tuesday by the Health, Labor and Welfare Ministry, a fairly high rate for a developed country.

The poverty rate for children was 14.2 percent that year, the ministry said. The Organization for Economic Cooperation and Development defines households with less than half the median national disposable income as poor. For Japan it was ¥1.14 million in 2006.

The OECD has published the poverty rates for member countries through 2004, but the Japanese government had not previously calculated the rate.

The rate in Japan "is quite high among the OECD countries," welfare minister Akira Nagatsuma said at a news conference.

According to an OECD report on poverty rates in the mid-2000s, Japan had the fourth-highest rate of relative poverty among OECD member countries.

"Once the poverty rate is announced (by the government), you will be able to check if the figure goes up or down under the administration," welfare parliamentary secretary Kazunori Yamanoi said.

Nagatsuma stressed that the poverty rate for single-parent households is particularly high in Japan at 58.7 percent in 2004, according to OECD figures.

'It's the worst in the member countries," he said, adding that the government will hammer out measures to improve the lives of children living in relative poverty.

Nagatsuma said the government will strive to cut the poverty rate after estimating how steps to support children affect household finances. In April, the previous administration ended a single-parent allowance of about ¥23,000 a month despite the country's high child-poverty rate, drawing fire from welfare experts.

The Hatoyama administration plans to reinstate the allowance in December and is expected to eventually provide child allowances totaling ¥26,000 per child per month, and to scrap tuition for high school students.