TOKYO (AFP) - The number of people aged 100 and above has hit 60,000 in Japan this year, as the country faces spiralling social and health expenses to look after its legions of retirees.

The population of centenarians is expected to reach 61,568 next week, of which 87 per cent will be women, the Welfare Ministry said on Friday (Sept 11).

On Sept 15, when the country marks Senior's Day, the government will give letters and commemorative gifts to the 30,379 people who turn 100 this year.

They will receive a silver sake dish that now costs the equivalent of US$65 (S$92), but since Japan's ageing population is ballooning, the ministry is eyeing a cheaper alternative for the gift from next year.

Presenting centenarians with the expensive gift was fine in the first year of the programme - 1963 - when Tokyo gave just 153 dishes to those who passed the century mark.

But the number of 100-year-olds in Japan has boomed since, with nearly 30,000 people eligible for the annual gift in 2014, at a cost of 260 million yen (S$3 million).

Japanese men on average live just over 80 years, while women boast the world's longest life expectancy of 86.83 years.

The country is also home to the world's oldest man, Mr Yasutaro Koide, who turned 112 years old in March.