The reports come after Trump announced a trade deal with Japan, and days after Ishiba's governing coalition lost its majority in the country's upper house.

Japanese Prime Minister Shigeru Ishiba plans to announce his resignation by the end of next month, the Mainichi newspaper reported on Wednesday.

Embattled Japanese Prime Minister Shigeru Ishiba has decided to disclose his plans to step down by August given the results of the upper house election, according to the Mainichi newspaper.

Mr Ishiba, who has faced mounting criticism from within his Liberal Democratic Party (LDP) after his coalition lost its majority in Sunday’s upper house election, has reportedly informed close aides of his intention to resign.

Japan's Prime Minister Shigeru Ishiba plans to announce his resignation by the end of next month, media said on Wednesday, following a bruising defeat in an upper house election. That step would trigger a leadership race in his Liberal Democratic Party (LDP),

The embattled prime minister said he would remain in office to oversee tariff talks with the United States and other pressing matters.