Japanese Prime Minister Kishida Fumio says he has no plans for a snap election after the opposition Constitutional Democratic Party took all seats in three by-elections on the weekend.

The main ruling Liberal Democratic Party did not field a candidate in two of those constituencies, but lost the other in Shimane Prefecture.

Kishida said on Tuesday that a simmering money scandal is taking its toll. He said: "The LDP's political fundraising issue proved to be a major factor during the Shimane election campaign. I am very sorry for the defeat -- both to the candidate and to all of the local people who gave him their support."

The prime minister vows to fulfill his duties, including as LDP president. Kishida says he will work to restore public trust through political and party reforms, as well as by tackling rising prices.

Lawmakers in the CDP will now be heaping pressure on Kishida in the Diet. But he says he has no intention of dissolving the Lower House.