CEO Louis C. Camilleri’s statement was in response to comments at its annual shareholder meeting in New York. Executives from the seller of Marlboro and other brands overseas spent most of the gathering sparring with members of anti-tobacco and other corporate accountability groups.

The nurse, later identified as Elisabeth Gundersen from the University of California-San Francisco, cited statistics that tobacco use kills more than 400,000 Americans and 5 million people worldwide each year. She is a member of The Nightingales Nurses, an activist group that works to focus public attention on the tobacco industry.

Gundersen also said a patient told her last week that of all the addictions he’s beaten — crack, cocaine, meth — cigarettes have been the most difficult.

In response, the often-unapologetic Camilleri said: “We take our responsibility very seriously, and I don’t think we get enough recognition for the efforts we make to ensure that there is effective worldwide regulation of a product that is harmful and that is addictive. Nevertheless, whilst it is addictive, it is not that hard to quit. … There are more previous smokers in America today than current smokers.”

Camilleri is a longtime smoker. An April 2009 BusinessWeek article quoted him as saying he had quit only once, for three months when he had a cold. Following Wednesday’s meeting, the company reiterated its position that “tobacco products are addictive and harmful.”

Matthew Myers, president of the Campaign for Tobacco-Free Kids said the comments represent the “most irresponsible form of corporate double-speak.”

“Study after study has documented the powerful addiction to cigarettes is one of the most difficult to overcome of any drug anywhere in the world,” Myers said. “It is stunning in the face of overwhelming science for the leader of the world’s largest private tobacco company to deny how difficult and addictive cigarettes are.”

Morningstar analyst Philip Gorham said addictiveness is why tobacco is such a profitable business.

“It’s in the interest of executives to give the impression that they don’t want new smokers to take up smoking, that they believe that people who do, can quit, but the statistics tell another story,” Gorham said.

There are more 1 billion tobacco users in the world, according to the World Health Organization. While global figures are not widely available, the U.S. Public Health Service says about 45 percent of U.S. smokers try to quit each year, and only 4 to 7 percent of them are successful.

During the meeting, Camilleri also discussed the challenges facing the tobacco industry like tax hikes and regulation, including bans on product displays, ingredients and colorful packaging. He said some of these restrictions impede competition, add costs for retailers, encourage adult smokers to make choices purely on price and foster black markets.

He also said Philip Morris International has successfully managed regulation in the past such as public smoking restrictions, marketing constraints and graphic warning labels.

“In fact, we have largely supported these measures within the framework of comprehensive, effective, and uniform tobacco regulation,” Camilleri said. “We do not, however, support regulation that prevents adults from buying and using tobacco products, or that imposes unnecessary impediments to the operation of the legitimate tobacco market.”

Last year, Philip Morris International saw its profit grow 14.5 percent as its net revenue excluding excise taxes rose 8.7 percent. The company has raised prices and focused on emerging markets for growth as cigarette demand falls.

Philip Morris International, with offices in New York and Lausanne, Switzerland, was spun off from Richmond, Va.-based Altria in March 2008. Altria still sells Marlboro and other Philip Morris brands in the U.S.

Philip Morris International is the world’s largest non-governmental cigarette seller, smaller only than state-controlled China National Tobacco Corp.