TOKYO, July 21 (Xinhua) -- Japanese Prime Minister Shigeru Ishiba on Monday vowed to stay in office despite a significant electoral setback in the House of Councillors election, where the ruling Liberal Democratic Party (LDP) and its coalition partner failed to secure a majority.

Speaking at a press conference on Monday afternoon, Ishiba acknowledged the disappointing results and expressed a strong sense of responsibility.

"What is most important right now is to avoid causing stagnation in national politics," he said, vowing efforts to fulfill the responsibilities as the leading party.

His remarks came amid growing public dissatisfaction over rising living costs and policy missteps, which analysts say contributed to the poor performance of the ruling bloc.

According to the final vote count completed in the early hours of Monday, the LDP secured only 39 seats of the 125 contested seats in the upper house election, while Komeito took eight, below their combined target of 50.

Even with their existing non-contested seats of 75, they now held fewer than the 125 seats needed for a majority in the 248-member upper chamber.

Despite the setback, Ishiba emphasized the need for stability and continuity in government, and formally declared his intention to continue serving as prime minister. ■