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.

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 that included calling for tougher restrictions on foreigners and the curtailment of gender equality and diversity policies.

Its leader is a former supermarket manager who created his political party on YouTube in the depths of the coronavirus pandemic and campaigned on the Trumpian message “Japanese First.”

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

World markets are mixed after U.S. stock indexes hit new records. Oil prices fell and U.S. futures were little changed.

Japanese markets were closed for a holiday, but the rise in the yen and Nikkei futures showed investors had already priced in the election outcome.

Japan is seeking to crack down on foreign interference in national elections through the spread of false information, which has been made easier through the internet and artificial intelligence.