The government's move to ban smoking in indoor public places ahead of the 2020 Tokyo Olympics has hit a snag due to staunch resistance from lawmakers in the ruling Liberal Democratic Party trumpeting smokers' rights and the need to protect the tobacco industry.

But if Japan stalls in its attempts to push anti-smoking legislation through the Diet, it could be "singled out" for violating an international treaty on tobacco control, to which it is a signatory, warns a health governance expert at a United Nations University-linked research institute.

In 2004, Japan joined the WHO Framework Convention on Tobacco Control (FCTC), the first international public health treaty, which went into force in 2005. Now signed by 179 countries and the European Union, the FCTC aims to reduce demand for tobacco consumption and protect the public from exposure to tobacco smoke.