Tokyo - Japanese girls born last year can expect to live to an average age of 85.8 years, making them the longest-lived in the world, according to figures released by the government on Thursday.

Their male compatriots fare less well, with a life expectancy of 79 years, second to Icelandic men at 79.4 years, the Health Ministry said.

Japan's women have topped the world's longevity ranks for 22 years, something researchers have attributed to their healthy diet and tight social ties, among other factors.

Improved treatment of the ageing population's three biggest killers -- cancer, heart disease and stroke -- has helped push life expectancy to record highs, a ministry official said.

After the Japanese, women in China's Taiwan are the world's second longest-lived at 84.6 years, then Spanish and Swiss women at 83.9 years, the report said.

The Guinness Book of World Records lists Japan's 114-year-old Yone Minagawa and 111-year-old Tomoji Tanabe, as the world's oldest person and oldest man, respectively.

But increasing life expectancy and a scarcity of babies in Japan have fuelled concern about how the world's oldest society will fund its pension requirements.