The loss on Sunday left the Liberal Democrats a minority party in both houses of Parliament, while two new nationalist parties surged.

Japanese Prime Minister Shigeru Ishiba, under growing pressure to step down over the historic loss of his ruling party in a weekend election, says he will decide on whether to resign after closely studying the tariff deal just struck with the United States.

Japan's far-right populist Sanseito party was one of the biggest winners in the weekend's upper house election, attracting many voters with its "Japanese First" platform.

After months of fraught negotiations with the United States, Japan clinched a deal just days before punitive tariffs were scheduled to take effect.

Japanese Prime Minister Shigeru Ishiba will announce his resignation by the end of next month, Japanese media reported on Wednesday, following a bruising election defeat that cost his administration its upper house majority.

The road to Japan’s trade deal with the U.S. just got longer and more winding as Prime Minister Shigeru Ishiba’s coalition lost its majority in the upper house following the election held on Sunday. It was only in late October that Ishiba’s Liberal Democratic Party lost the majority in the lower house it had held since 2012.

Japanese Prime Minister Shigeru Ishiba plans to step down following a bruising upper house election defeat, a source told Reuters, as the embattled premier announced a long-sought trade deal with U.S.