TOKYO, DEC. 10 (THURSDAY) -- Millions of children continue to die each year due to poor nutrition and disease, but wider access to vaccines and basic medical care has substantially reduced the number of deaths in the past few years, according to a report by the United Nations Children's Fund released here today.

UNICEF executive director James P. Grant, in Tokyo to publicize the report on "The State of the World's Children," said that with the exception of war-torn areas, infant and child mortality statistics are improving worldwide.

The annual report was released in Japan in part because this island nation has the lowest infant mortality rate in the world, easily surpassing the United States.

Before World War II, Japan's child death rate was as high as India's is today, but affluence, good nutrition, rigorous prenatal and postnatal care and universal vaccination against childhood diseases brought a drastic reduction in deaths.

Today, Grant said, only about 20 children under 5 years old die each day here, giving Japan an infant mortality rate about one-quarter that of the District of Columbia, which has the highest rate in the United States.

While poor countries cannot afford the advanced medical care or good nutrition of a country like Japan, Grant said that recent developments have made it easier to prevent dehydration, fatal to many children, and to widen the use of vaccines that can prevent the six major diseases, including diptheria, tetanus and measles, that claim about 4.5 million children each year.