The world's first treaty aimed at cutting tobacco-related deaths has come into force. The World Health Organization's Framework Convention on Tobacco Control becomes legally binding upon countries that have ratified the landmark agreement.

The World Health Organization says it believes the Tobacco Convention, the world's first international public health treaty, could save millions of lives. The WHO says tobacco is the second leading cause of preventable deaths globally after hypertension.

The WHO estimates that nearly five million people die prematurely every year from tobacco-related diseases. If current smoking trends are not reversed, the WHO warns by 2020, tobacco will kill 10 million people a year, 70 percent of them in developing countries.

The coordinator of the WHO's Framework Convention on Tobacco Control, Douglas Bettcher, says the treaty is a tool that, if properly implemented, can curb the global tobacco epidemic.

"It is an historical moment and we are very confident that this treaty is going to save lives," said Douglas Bettcher. "It has already started off a powerful process globally and we are very confident that it is going to continue to do so and it is going to prove itself as a very effective public health tool to really curb this unacceptable burden of disease and death."

In all, 167 countries have signed the treaty. But, it is legally binding only for the 57 countries that have ratified it. The treaty sets standards and guidelines for tobacco advertising, pricing and smuggling. It also aims to limit non-smokers' exposure to other people's smoke.

Anti-tobacco activists are concerned that the treaty will be weakened because powerful countries such as the United States and China have not yet ratified it. However, they point out that some of the largest tobacco growers, such as India, as well as big cigarette-producing countries, such as Britain and Turkey, have become part of the treaty.

The director of the WHO's Tobacco Free Initiative, Vera Luiza da Costa e Silva says treaty provisions aim to dissuade children from smoking and helping adults to kick the habit.

"The ban of advertising so as not to promote smoking propaganda, publicity, sponsorship and promotion," said Vera Luiza da Costa e Silva. "Measures to raise taxes and prices. One of the most important measures that I can describe is the measure that addresses smuggling, which is a big cause of increasing availability of cigarettes with small prices and cigarettes of totally unknown origin."

WHO officials accuse the tobacco industry of trying to subvert the treaty by pressuring countries not to ratify it. Leading tobacco companies, such as British-American Tobacco and Philip Morris, deny these charges. They are on record as saying that they believe the treaty is important and they support it.