Japan will sign the first global treaty aimed at reducing the health hazards of smoking.

The Framework Convention on Tobacco Control, adopted by the World Health Organization in May, will be presented to the Diet for ratification after the signing takes place, government officials said Tuesday. The Diet will sign the treaty by the end of the month at the earliest, they said.

The treaty obliges tobacco companies to print health warnings that cover at least 30 percent of cigarette packaging, and to take steps to prevent minors from buying cigarettes from vending machines.

Ninety-one nations have signed the treaty and nine have ratified it. The treaty will take effect 90 days after 40 countries ratify it.

The Finance Ministry will change its guidelines to force tobacco companies to admit on their packaging that smoking causes diseases, such as lung cancer.

Under the new guidelines, companies whose products include phrases such as "mild" or "light" in their names must warn consumers that such words do not mean the products have a reduced negative impact on their health.

The Tobacco Institute of Japan, a tobacco manufacturers' trade group, has drawn up its own steps for regulating tobacco ads.

Manufacturers would refrain from advertising cigarettes through public transportation systems -- including trains, buses and taxis -- as well as in highly public areas, such as train stations. Cigarette ads would only be permitted in designated smoking areas in such facilities. The makers would also limit newspaper ads.