Prime Minister Fumio Kishida on Sunday asked ruling party lawmakers to unite as one to clinch a victory in the upcoming House of Councilors election and ensure a stable coalition government as Japan confronts "history-making" challenges such as COVID-19 and Russia's invasion of Ukraine.

Kishida, who spoke as president of the Liberal Democratic Party at its convention, underscored the importance of its coalition with its junior partner Komeito, dismissing an emerging view that their relationship has become awkward over cooperation in the election, possibly in July.

"Is there any other option than LDP-Komeito that can be entrusted with governing the country when we face history-making challenges? I don't think so," Kishida told the convention.