Mr Ishiba has been under growing pressure to step down as his ruling Liberal Democratic Party (LDP) and its junior coalition partner, Komeito, lost their majority in the 248-member upper house, the smaller and less powerful of Japan's two-chamber parliament on Sunday, shaking his grip on power and Japan's political stability.

With the trade deal with the U.S. now done, Japanese Prime Minister Shigeru Ishiba is reportedly planning to step down. A Bloomberg report, citing the Yomiuri newspaper, stated that Ishiba is set to announce his resignation this month.

By Tim Kelly, Satoshi Sugiyama and Leika Kihara TOKYO (Reuters) -Japanese Prime Minister Shigeru Ishiba denied on Wednesday he had decided to quit after a source and media reports said he planned to announce his resignation to take responsibility for a bruising upper house election defeat.

Embattled Japanese Prime Minister Shigeru Ishiba denied media reports that he is set to announce his resignation, in an apparent bid to extend his premiership despite an election setback earlier in the week.

Japanese PM Shigeru Ishiba's political future hinges on tariff negotiations following a trade deal announced by Trump. Ishiba plans to assess the agreement's impact before deciding on his position, amid declining support and pressure from his party after recent electoral losses.

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.

An emerging U.S.-Japanese trade deal could unlock major investment, avert a potential shock to the global economy and may deliver political wins for both U.S. President Donald Trump and Japanese Prime Minister Shigeru Ishiba,