TOKYO -- Shigeru Ishiba vowed to stay on as Japan's prime minister after his ruling Liberal Democratic Party (LDP) and coalition partner Komeito appeared to be on course to lose their upper house majority following Sunday's election, local media reported.

"We have to take the projected outcome humbly," Ishiba said on a TV program, adding that "we must be fully aware of our responsibilities as the largest party in parliament. I want to be fully conscious of my own responsibility to properly address the issues" facing the country, according to Kyodo News.

Ishiba made the remarks after LDP Secretary-General Hiroshi Moriyama, the No. 2 figure in the party, said during a separate TV program that "we should not create a political vacuum."

Exit polls showed the ruling coalition of the LDP and Komeito is likely to lose its majority in the 248-seat House of Councillors following the election.

Currently, the coalition has 75 seats that are not up for re-election. It must win at least 50 of the 125 contested seats to clear the majority line. They are forecast to secure 32 to 51 seats, the public broadcaster NHK projected.

The embattled prime minister is expected to hold a press conference on Monday, as senior figures in the country's major opposition parties expressed reluctance to help the ruling bloc by forming an expanded coalition.

In the October 2024 general election, the ruling coalition already lost its majority in the more powerful House of Representatives, or lower house, forcing Ishiba to form Japan's first minority government in over three decades.