Japan's ruling party will choose Prime Minister Shinzo Abe's successor around September 15, after he
The president of Abe's Liberal Democratic Party is virtually assured of being prime minister because of the LDP's majority in parliament's lower house.
Abe's announcement on Friday that he is stepping down, after a worsening of the ulcerative colitis he has battled for years, marks the end of his tenure and the start of a several-week race to replace Japan's longest-serving premier.
In a news conference, Abe declined to name a preferred successor. Former defence minister Shigeru Ishiba and former foreign minister Fumio Kishida indicated they intend to run, while Chief Cabinet Secretary Yoshihide Suga and Defence Minister Taro Kono are considered among the potential candidates.
Shinzo Abe bows after he was officially elected Japan's new prime minister in 2012. Source: AAP
Deputy Prime Minister Taro Aso, a former prime minister who is also Abe's finance minister, said he did not plan to join the race to succeed Abe, Kyodo said.
Abe said it is up to the LDP leadership to determine the schedule of the party election but that he believes his health will hold up until a successor is chosen.
Usually, the party must announce the leadership election a month in advance, but in the case of a sudden resignation, an extraordinary vote can be called "at the soonest date possible" among members of parliament and local LDP chapters.
The main scenario is for the election to be held on September 15, Kyodo said, while the format and date will be decided on Tuesday, media reported.
Combined file photo shows Japanese Defense Minister Taro Kono (L) and Chief Cabinet Secretary Yoshihide Suga, who are among the candidates to succeed Abe. Source: AAP
'Support has been enormous'
US President Donald Trump paid his "highest respect" to Abe and voiced concern over his "great friend" resigning.
"I want to pay my highest respect to Prime Minister Shinzo Abe, a very great friend of mine," Trump told reporters aboard Air Force One as he returned from a campaign rally in New Hampshire.
"We've had a great relationship and I just feel very badly about it, because it must be very severe for him to leave."
"He loves his country so much and for him to leave, you know, I just can't imagine what it is. He's a great gentleman and so I'm just paying my highest respect," Trump added.
German Chancellor Angela Merkel said she "regrets" Abe's resignation, hailing his "fight for multilateralism".
US President Donald J.Trump (L) shakes hands with Japanese Prime Minister Shinzo Abe (R) Source: AAP
Merkel said she and her fellow veteran leader in the Group of Seven industrialised nations had a "shared foundation of values".
"I of course regret his resignation and wish him all the best for his health," she told reporters. "We always worked very, very well together... He was always someone who committed himself to the fight for multilateralism."
Prime Minister Scott Morrison hailed Abe as "Australia's true friend".
Mr Morrison said Japan was one of Australia's closest partners, "propelled by Prime Minister Abe's personal leadership and vision, including elevating the relationship to new heights under our Special Strategic Partnership".
Olympic powerbroker John Coates paid tribute to Abe for his commitment to hosting the Tokyo Games, which have been postponed due to COVID-19.
He praised Abe's commitment to the global sporting event, saying his "support has been enormous", and his role in managing its difficulties.
"This is disappointing news from a professional and personal perspective. My interactions with him have always been very positive and constructive," Coates said in a statement.
