Il Nuovo Postiglione - Japan PM Ishiba says he will resign

The announcement means fresh uncertainty for the world's fourth-largest economy as it battles rising food prices and deals with the fallout of US tariffs on its vital auto sector.

"Now that negotiations on US tariff measures have reached a conclusion, I believe this is the appropriate moment," Ishiba told a news conference.

"I have decided to step aside and make way for the next generation," he said.

US President Donald Trump signed an order on Thursday to lower tariffs on Japanese autos, with Washington finally moving to implement a trade pact negotiated with Tokyo in July.

However, although Japanese autos will now face a 15 percent tariff instead of the current 27.5 percent, the levy will still cause significant pain in the crucial industry.

The decision comes less than a year after the 68-year-old, seen as a safe pair of hands, took the helm of the long-dominant Liberal Democratic Party (LDP).

He won the party leadership in September 2024 to become the LDP's 10th separate prime minister since 2000, all of them men.

Media reports said earlier that Ishiba wanted to avoid a split in the party and that he was unable to withstand the mounting calls for his resignation.

The farm minister and a former prime minister reportedly met with Ishiba on Saturday night to urge him to resign voluntarily.

Four senior LDP officials, including the party's number two Hiroshi Moriyama, offered to resign last week.

Opponents of Ishiba had been calling for him to step down to take responsibility for the election results, following the upper chamber vote in July.

Those backing the move included Taro Aso, the influential 84-year-old former prime minister, according to Japanese media.

Ishiba's term as party leader was supposed to end in September 2027.

His most prominent rival Sanae Takaichi, who is seen as a hardline nationalist, all but said on Tuesday that she would seek a contest.

Voters are less than keen on the hawkish Takaichi, runner-up in the last leadership election in 2024.

A Nikkei survey held at the end of August put Takaichi as the most "fitting" successor to Ishiba, followed by farm minister Shinjiro Koizumi, but 52 percent of respondents said a leadership contest was unnecessary.

After the election, social media users called for the moderate Ishiba to remain in power under the hashtag "#Ishiba Don't quit".

The LDP has governed almost continuously since 1955, but voters have been deserting the party, including towards fringe groups such as the populist Sanseito.

Factors include rising prices, notably for rice, falling living standards, and anger at corruption scandals within the LDP.

Ishiba, a diligent career politician, was elected LDP leader last year on his fifth attempt, promising a "new Japan".

F.dAangelo--INP