The Diet on Wednesday passed an amendment that will ban smoking in public facilities for the first time as the nation — long deemed a haven for smokers — scrambles to combat secondhand smoke in the lead-up to the 2020 Tokyo Games.

The ban will be implemented in stages, coming into full force by April 2020.

The revision to the Health Promotion Law, however, has been significantly watered down from the health ministry's original proposal, falling short of a comprehensive smoking ban in restaurants and bars.