In the video, the 1976 Olympic champion assured his fellow athletes that "you can be sure that you can make your Olympic dream come true" with the "good news" that "we all will be able to celebrate the Olympic Games Tokyo 2020, even if it's only in 2021."
President Bach explained his phone call with Japanese prime minister Abe Shinzo, and spoke of the reasoning behind the unprecedented decision to postpone the Games.
The German also acknowledged that uncertainty remained, including "for the entire humanity".
"We will work hard now to undertake this extremely challenging task of postponing the Games and of organising postponed Games, which have never happened before, so we have no blueprint for this," President Bach noted.
"It will need the effort of everybody and the contribution of all to make this happen, because the Olympic Games are the most complex event on this planet.
"We want to provide you with the best conditions and the safest environment for these Games."