The treaty, known as the Framework Convention on Tobacco Control, was finalised in May 2003 and came into force earlier this year, the UN said on Tuesday.
The parties who have ratified it are scheduled to meet for the first time in Geneva in February.
The treaty requires countries that ratify it to restrict tobacco advertising and sponsorship, put tougher health warnings on cigarettes and limit the use of language like "low-tar" and "light".
They also are meant to enact price and tax hikes, create controls on second hand smoke and sales of cigarettes to youngsters, as well as clamp down on smuggling.
UN associate spokesman Farhan Haq said 106 countries ratified the treaty by Tuesday's deadline for participation at the February meeting expected.
Corporate Accountability International, a Boston-based organisation which campaigns against dangerous corporate actions around the world, said countries covering over 70% of the world's population have ratified the treaty.
"The progress is a true testimony to the growing global commitment to protect people's lives over big tobacco's profits"
Director of Corporate Accountability International's Campaigns
They include Australia, Brazil, Britain, Canada, China, France, Germany, India, Japan, Saudi Arabia, South Africa and Turkey.
"The progress is a true testimony to the growing global commitment to protect people's lives over big tobacco's profits," Corporate Accountability International's Campaigns Director Patti Lynn said in a statement.
The organisation criticised President George Bush's administration, which signed the treaty on 10 May 2004, for failing to submit it to the Senate for ratification.
The accord aims to reduce substantially the number of deaths from tobacco-related illnesses - such as cancer and heart disease - which the World Health Organisation estimates kill one smoker every 6.5 seconds.
There are an estimated 1.2 billion smokers in the world.