Abe announced on Friday (August 28) that he is stepping down for health reasons.

Abe, who suffers from ulcerative colitis, is Japan's longest-serving Prime Minister, having been in the office since 2012.

"I have enormous respect for Prime Minister Abe and certainly wish him well", Coates said. 

"This is disappointing news from a professional and personal perspective. 

"My interactions with him have always been very positive and constructive."

Abe heavily backed Tokyo's bid to host the 2020 Olympic and Paralympic Games, speaking at the 125th IOC Session in 2013 where the Japanese capital was awarded hosting rights.

He was "a champion of Japan’s preparations for the Tokyo Olympic Games", IOC vice-president Coates said.

As the coronavirus crisis came to dominate the build-up to the Games, it was Abe and IOC President Thomas Bach who agreed to postpone the event until 2021 - meaning Abe will now be out of office is the Olympics and Paralympics can indeed go ahead next year.

"With his Government’s firm commitment, the Tokyo Olympic Games Organising Committee’s readiness to host the Olympic Games was quite extraordinary", Coates added.

"Japan was ready, but due to COVID we now look to next year.

"I certainly hope he can successfully overcome the current challenges he faces away from political office and I am sure a smooth transition will follow to ensure Japan’s momentum can continue.

"I very much look forward to PM Abe joining us for the Opening Ceremony on 23 July 2021 in the new National Stadium that he was instrumental in delivering.

"His support has been enormous."

Abe will remain Prime Minister until the Liberal Democratic Party chooses a new leader.

Per Japanese news agency Kyodo, that will happen on or around September 15, with Shigeru Ishiba, Fumio Kishida and Yoshihide Suga in the running to replace Abe.

Bach has also had kind words for the departing Abe, saying that he "could always be trusted" and was a "strong partner".