Americans are living longer than ever, with the average life expectancy reaching 78 years in 2005, the Centres for Disease Control and Prevention (CDC) said.
But despite the steady upward climb of longevity, the United States was still far behind Japan, Andorra and Italy, where statistics compiled by the World Health Organization (WHO) show that life expectancy exceeds 80 years.
The CDC report, based on preliminary data for 2005, showed that life expectancy in the United States has risen steadily in the past 50 years.
Americans lived for around 69 years in 1955, and 76 years in 1995, the study showed.
The age-adjusted death rate also fell to an all-time low in 2005, bottoming out at fewer than 800 deaths per 100,000 people, the statistics show.
"This report highlights the continued reduction in deaths from the three leading killers in the United States - heart disease, cancer and stroke - which is most likely due to better prevention efforts and medical advances in the treatments of these diseases," said Hsiang-Ching Kung, a survey statistician at the CDC and one of the report's authors.
The death rate from heart disease fell to 210.3 per 100,000 in 2005 from 217 per 100,000 the previous year.
Deaths from cancer fell from 185.8 per 100,000 to 183.8 per 100,000 during the same period, and stroke deaths fell from 50 to around 47 per 100,000.
"If death rates from certain leading causes of death continue to decline, we should continue to see improvements in life expectancy," Kung said.
On a sour note, however, the death rate from Alzheimer's and Parkinson's diseases both increased by around five percent year-on-year.
Alzheimer's disease is the seventh leading cause of death in the United States and Parkinson's the 14th.
White Americans' average life expectancy was just over 78 years, or five years longer than African-Americans, according to the study.
The longer life expectancy in the United States puts the country on par with the likes of Brunei, Cuba and Kuwait, according to WHO statistics.
The country with the lowest life expectancy in the world is Zimbabwe, where people can expect to live around 36 years, data from WHO show.