Plain packaging for cigarettes "kills the glamour" of smoking, the head of the World Health Organisation (WHO) has said.
The measure reduces the attractiveness of tobacco products, Dr Margaret Chan added.
Earlier this month, the UK began to implement plain packaging for tobacco products. Cigarettes are being sold in standardised green packaging bearing graphic warnings of the dangers of smoking.
All packs must contain a minimum of 20 cigarettes to make sure the packs are big enough for health warnings to cover 65% of the front and back, with the brand name restricted to a standard size, font and colour.
Packaging of hand-rolled tobacco must also be in the same drab green colour and contain a minimum of 30g of tobacco.
Tobacco giants now have a year to sell old stock and fully implement the changes.
-- WHO/Europe (@WHO_Europe) May 31, 2016
To mark World No Tobacco Day, the WHO has highlighted the concept and has drawn conclusions from Australia, which became the first country in the world to implement plain packaging in December 2012.
Dr Chan said: "Plain packaging reduces the attractiveness of tobacco products. It kills the glamour, which is appropriate for a product that kills people.
"It restricts tobacco advertising and promotion. It limits misleading packaging and labelling. And it increases the effectiveness of health warnings."