A public health treaty, aimed at curbing tobacco sales and advertising, is set to come into force in three months time.
Countries around the world have ratified the treaty
Peru became the 40th country to sign up to the World Health Organization's Framework Convention on Tobacco Control.
The treaty was agreed by the WHO's 192 member states in 2003 after four years of negotiations.
But 40 countries had to ratify the treaty for it to come into force.
Countries who sign up to the treaty will be required to ban adverts and sponsorship promoting tobacco products, forbid sales to children and force companies to print larger health warnings on cigarette packs.
They also agree to use taxation to reduce consumption and to clamp down on smuggling.
A spokesman for the Department of Health said the UK was set to ratify the treaty later this month.
A death every six seconds
Iain Simpson of the WHO said: "This is a major public health treaty, which will give people protection from tobacco for the first time."
"There are 40 countries at the moment but we hope there will be
The WHO has warned one person dies every six-and-a-half seconds, and many more fall ill from tobacco use.
This places increasing pressure on health care and has a significant impact on economies, it says.
About 84% of smokers live in developing countries - and it is there that the tobacco epidemic is still growing.