Japanese Prime Minister Shinzo Abe will remain in hospital indefinitely with stress-related stomach problems.
Mr Abe was hospitalised the following day for exhaustion and stress-related stomach problems. The stay was expected to last for three to four days.
The government still has no plans to name an acting premier.
Leaders of Mr Abe's ruling Liberal Democratic Party (LDP) and the main opposition Democratic Party agreed to hold an election in parliament September 25 to name his replacement as prime minister, although this still has to be formally approved.
Two LDP candidates are vying to replace Mr Abe, who abruptly announced he was resigning last Wednesday.
As chief cabinet secretary, Kaoru Yosano has taken over many of Mr Abe's day-to-day responsibilities.
Yasuo Fukuda, a veteran moderate widely considered the front-runner, and the more hawkish former Foreign Minister Taro Aso are the only candidates in a September 23rd race to replace Mr Abe as chief of the ruling party.
The new leader of the LDP is ensured election as prime minister because of the party's majority in the lower house of parliament.
AP