The World Health Organization Framework Convention on Tobacco Control (WHO FCTC) is a treaty adopted by the 56th World Health Assembly on 21 May 2003. It became the first World Health Organization treaty adopted under article 19 of the WHO constitution. The treaty came into force on 27 February 2005. It had been signed by 168 countries and is legally binding in 180 ratifying countries. There are currently 16 United Nations member states that are non-parties to the treaty (nine which have not signed and seven of which have signed but not ratified).