Kishida's popularity and his standing within the ruling party have dived since he took office in October 2021, and many voters are not happy with his government's handling of the world's third-largest economy.

The 66-year-old will stand for re-election next year as president of the fractious Liberal Democratic Party, which has dominated politics for decades, and experts said the cabinet reshuffle was an attempt to shore up his approval ratings.

Foreign Minister Yoshimasa Hayashi was replaced by Yoko Kamikawa, one of five women in the new cabinet, chief cabinet secretary and government spokesman Hirokazu Matsuno told reporters.

Kamikawa, 70, is Japan's first woman foreign minister in 19 years.

She was justice minister five years ago when Japan executed the leader and members of the Aum Shinrikyo cult for their role in the deadly 1995 sarin attack on the Tokyo subway.

Minoru Kihara, 54, succeeded Yasukazu Hamada as defence minister, just as Japan faces a rising threat from North Korea and deteriorating relations with China.

Public support for the Kishida government stood at just 36 percent against 43 percent for disapproval, according to a poll released Monday by national broadcaster NHK.

A majority of voters are not satisfied with the government's policy to address inflation, according to a Yomiuri poll published last month.

Kishida said Sunday that he plans to "implement a bold economic package" to address the impact of rising prices on voters.

And he stuck with his economic team in the reshuffle.

Shunichi Suzuki stays as finance minister and Yasutoshi Nishimura retains the ministry of economy, trade and industry ministry.

Kishida's flamboyant former rival Taro Kono remains in charge of digital affairs.

Farm minister Tetsuro Nomura, who recently made a gaffe about the release of waste water from the disaster-hit Fukushima nuclear plant, was replaced.

- 'Rank hypocrisy' -

"The cabinet shuffle is, as usual, an attempt to shore up faltering approval ratings," said Brad Glosserman at Pacific Forum research institute.

It aims to make Kishida's internal re-election "more likely by boosting public support (and) to ensure that factions within the LDP continue to support him," he told AFP.

Public support has been hit in recent months due to issues including the troubled new "My Number Card" identification system.

Scandals have also taken their toll, including "inappropriate behaviour" by Kishida's son, who was removed from the position of his secretary earlier this year.

Magazine photos showed invitees to a party thrown by Shotaro Kishida pretending to hold a press conference and one lying down on red-carpeted stairs.

In the reshuffled cabinet, five of the 19 ministers are women, up from two previously.

That is the joint highest number in Japan's history.

In June, Kishida's government set new rules that top listed firms should by 2025 have at least one woman director, and that by 2030 women should form 30 percent of boards.

His cabinet move "is an attempt to counter the rank hypocrisy by which successive governments call for greater participation of women in business yet provide virtually no representation in the cabinet," said Glosserman.

"Let's see how long they last."