Japan Tobacco Inc. says a proposal to triple cigarette prices through higher taxes would devastate the nation's tobacco industry and could hurt the share price of the world's third-largest publicly traded cigarette maker.

"It would be disastrous harm for consumers first and the industry as well," President Hiroshi Kimura said in an interview at the company's Tokyo headquarters Wednesday. "Any tax hike is going to be very challenging for us."

Lawmakers have proposed raising taxes for cigarettes, which sell here for less than a third of the U.K. price, to fund rising welfare costs in a country where smoking kills about 100,000 people a year. It comes as JT battles tobacco prices, a declining smoking rate and controls on vending-machine purchases, which account for more than half its domestic sales.