Mainichi: Japanese Prime Minister Ishiba to resign next month.

Mr. Ishiba is facing growing opposition within the Liberal Democratic Party (LDP) for his declaration that he will remain in power despite the ruling coalition's heavy defeat in the upper house election on July 20.

According to the Yomiuri newspaper, Ishiba told close associates on the evening of July 22 that he would explain how he takes responsibility for the election defeat after a solution is reached regarding trade negotiations.

In a post on Truth Social on the morning of July 23rd (Asian time), US President Donald Trump announced that he had just finalized a "massive" deal with Japan, including $550 billion in investment in the US.

Speaking after Trump's post, Ishiba said he was ready to meet or speak by phone with Trump after receiving a detailed briefing from Japan's top trade negotiator, Ryosei Akazawa, who was in Washington for negotiations.

"I can't say anything until I've carefully considered the outcome of the agreement," Ishiba told reporters when asked how the deal with Washington might affect his decision to resign.

In explaining his decision to remain in office, Ishiba stressed the need to avoid creating a political vacuum as Japan faces challenges, including difficult trade negotiations with the U.S., which would have a significant impact on its export-dependent economy.

"I will remain in office and do everything in my power to chart a course to address these challenges," Ishiba said at a press conference on July 21, adding that he intends to speak directly with Trump as soon as possible to bring about tangible results.

Mr. Ishiba is expected to meet with senior figures in the ruling party later on July 23 to discuss the election results.