The treaty requires signed countries to restrict tobacco advertising, sponsorship and promotion, set new labeling and clean indoor air controls and strengthen legislation to clamp down on tobacco smuggling.
At the time of its unanimous adoption last May by WHO's 192 members, the agency warned that the annual death toll of 4.9 million, if left unchecked, could double by 2020.
The tobacco epidemic is still expanding, especially in developing countries where currently seven out of every 10 tobacco-related deaths occur, according to WHO. At current rates, the total number of tobacco users is expected to rise to 1.7 billion by 2025 from 1.3 billion now.
The European Community (EC) has also signed the treaty as a regional economic integration organization, while its member states sign and ratify the treaty individually.