Girls born in Japan today are likely to live until the year 2095, some with a good chance of seeing the dawn of the next century thanks to the world's longest life expectancy, AP reported.
Japan's child mortality rates are also among the world's lowest, according to statistics published Thursday by the World Health Organization.
For every 1,000 babies of both sexes born in Japan, 996 will make it past their fifth birthday - a key indicator of the health of a nation. Most European countries fare equally well on child mortality, while the United States limps behind both in child mortality and life expectancy.
The tiny nation of San Marino, which is surrounded by Italy, has the world's lowest child mortality and boasts the longest average life span for men anywhere, at 81 years.
Children in the West African country of Sierra Leone and Afghanistan are at the other end of the scale. About a quarter will die before the age of five, and overall life expectancy is short.
Men in Sierra Leone live on average just 39 years, while women live to 43. In Afghanistan both sexes fare badly, with men and women living to 41 and 42, respectively.
The figures for 2007 are the latest available.
The data showed that some countries have made remarkable progress in increasing life expectancy since 1990 - partly by ending wars, partly through successful health initiatives, and child mortality rates have been key.
"The decline in the death toll of children under five illustrates what can be achieved," said WHO's director of statistics, Ties Boerma.
The increased use of insecticide-treated mosquito nets for malaria, oral rehydration therapy for diarrhea, better access to vaccines and improved water and sanitation in developing countries are proving particularly effective, he said.
"The signs are really encouraging for many countries, and they weren't encouraging in the 1990s," said WHO's director of statistics, Ties Boerma.
Some 9 million children under 5 years old died in 2007, compared to 12.5 million in 1990.
Eritrea in East Africa increased its average life expectancy during that period by 33 years to 61 for men, and by 12 years to 65 for women. On the other side of the continent, in Liberia, the figure for men jumped 29 years to 54, and rose 13 years to 58 for women. Angola, Bangladesh, Maldives, Niger and East Timor also increased their average life expectancies for both men and women by full 10 years.
In the United States, life expectancy was on the rise for both sexes, but not so dramatically: up to 76 from 72 years for men, and to 81 from 79 for women.
The U.S., which spends the highest amount of money per person on health care - $6,719, also still lags on child mortality compared to other advanced nations. About eight in 1,000 children will die before the age of 5 - an improvement from 11 per 1,000 in 1990 but still twice as many as in Japan.
Other countries, meanwhile, showed a sharp decline since that time, especially in Africa, where AIDS and weak health systems take a heavy toll.
In Zimbabwe, a yearslong economic crisis and rampant inflation have created serious shortages of food and medicine and forced medical workers to flee the country. Those factors are among the reasons that women's life expectancy fell by 19 years to 44 and the men's average fell 12 years to 45.
The southern African nation of Lesotho recorded a 16-year drop for both men and women to 43 and 47 respectively. In the nearby kingdom of Swaziland, women live to 49 year on average, a drop of 14 years, while men's life expectancy declined by 12 years to 47.
Botswana, Congo, Kenya, South Africa and Zambia also reported significant drops in life expectancy for both sexes.
In Russia, the average life expectancy for men dropped to 60 from 64 years since the time of the Soviet Union. For women the drop was less marked, to 73 from 74 years.
The figures are only one of over 100 health indicators that WHO tracks in its 193 member states. Others include mother and child mortality; prevalence of diseases such as HIV, malaria and tuberculosis; access to doctors and medical facilities; and health expenditure per person.