A new US government report says smoking among US adults continues to fall.

The findings were released on Tuesday by The Centers for Disease Control and Prevention (CDC) released based on a large national survey.

Smokers comprised 42 per cent of the US population in 1965, and has dropped steadily over the years, the CDC pointed out. The smoking rate declined to 17 per cent last year, down from about 18 per cent in 2013.

The smoking rate had been falling for decades and according to experts the downtrend could be attributed to anti-smoking advertising campaigns, cigarette taxes, smoking bans, and the growing popularity of electronic cigarettes and other alternatives to traditional cigarettes.

The number of cigarette smokers in the US had dropped to about 15 per cent of the population, its lowest point in decades, according to US health authorities.

"The prevalence of current cigarette smoking among US adults declined from 24.7 per cent in 1997 to 15.2 per cent in January-March 2015," the report by the Centers for Disease Control and Prevention's National Center for Health Statistics said.

The figures would be updated when the entire year's data is available.

The report said smoking continued to be more common among men (17.4 per cent) than women (13.0 per cent).

Smoking was most common among African Americans (18.1 per cent), followed by whites (17.1 per cent) and Hispanics (10.4 per cent).

"The prevalence of current cigarette smoking among US adults declined from 24.7 per cent in 1997 to 15.2 per cent in January-March 2015," the report by the Centers for Disease Control and Prevention's National Center for Health Statistics said

The figures will be updated once the entire year's data is available.

According to the US surgeon general, smoking was known to cause "a host of cancers and other illnesses and is still the leading preventable cause of death in the United States, killing 480,000 people each year".

Smokers who successfully lowered their nicotine intake when they were switched to low-nicotine cigarettes were unable to curb their smoking habits in the long term, according to a study by researchers at University of California (UCSF) and San Francisco General Hospital and Trauma Center. (See: Low-nicotine cigarettes fail to sway smokers).

