Japan's incoming prime minister Ishiba Shigeru will officially assume his post at the Diet on Tuesday. He says he will call a snap election on October 27.

He said, "I believe it's important for our new administration to receive the public's mandate as soon as possible." Campaigning in the election will start on October 15.

Ishiba became leader of the main ruling Liberal Democratic Party last week.

Ishiba has appointed former Prime Minister Suga Yoshihide as the LDP's vice-president.

Moriyama Hiroshi is now the party's secretary-general, having previously served as General Council chairperson.

Finance Minister Suzuki Shunichi has taken over chairing the General Council.

Ishiba has appointed Former Defense Minister Onodera Itsunori as chairperson of the Policy Research Council.

And former Environment Minister Koizumi Shinjiro, who ran a close race against Ishiba for the LDP leadership, now heads the party's Election Strategy Committee.

Agriculture, Forestry and Fisheries Minister Sakamoto Tetsushi now chairs the Diet Affairs Committee.

And LDP Vice-President Aso Taro becomes the party's top adviser.

Ishiba will form his new Cabinet after he's elected prime minister in both Diet Chambers. The LDP intends to convene an extraordinary Diet session on Tuesday that will continue nine days.