BEIJING, June 12 (Xinhuanet) -- U.S. expected life span has surpassed 78 years for the first time in history, according to new government data released Thursday.

    The increase is due mainly to falling mortality rates in almost all the leading causes of death, including heart disease, cancer, accidents and diabetes.

     U.S. life expectancy has been steadily rising, usually by about two to three months from year to year. However, it continues to lag behind 30 other countries.

    World Health Organization data show that Japan has the longest life expectancy with Switzerland and Australia nearing the top of the list.

    "The international comparisons are not that appealing, but we may be in the process of catching up," said Samuel Preston, a University of Pennsylvania demographer.

    Life expectancy is up for both men and women, and whites and blacks in the United States. Although the gaps are closing, women continue to live longer, almost to 81, compared to about 75 for men.

    (Agencies)