Japan's prime minister promised "drastic" economic measures after reshuffling his cabinet and increasing the number of female ministers in an effort to boost his flagging popularity. 

Fumio Kishida's poll ratings and standing within the ruling party have dived since taking office in October 2021, with voters hit by rising prices in the world's third-largest economy.

Support for the government stood at just 36 percent, according to a poll released Monday by broadcaster NHK. Another survey showed most voters unhappy with efforts to tackle inflation.

Kishida said Wednesday he will order his new cabinet to form a "drastic" economic package to address the impact of rising prices on voters.

"With regard to economic measures, we must create drastic economic measures that are backed by the necessary budget under the new cabinet team, and implement them as soon as possible. I want this to be our top priority," Kishida told a news conference.

He stuck with his economic team in the reshuffle, with Shunichi Suzuki staying as finance minister and Yasutoshi Nishimura still in charge of economy and industry.

But the overhaul saw Yoko Kamikawa, a 70-year-old former justice minister, named Japan's first female foreign minister since 2004. She is one of five women in the new cabinet, equalling the previous highest number in Japanese political history.

Minoru Kihara, 54, became defence minister, just as Japan beefs up its military to face a rising threat from North Korea and deteriorating relations with China.

Kihara is a senior member of a non-partisan group aimed at promoting ties with Taiwan, the self-ruled island that Beijing sees as part of China.

- Factions -

Kishida, 66, will stand for re-election next year as president of the fractious Liberal Democratic Party, which has dominated Japanese politics for decades.

The reshuffle aims to make his re-election "more likely by boosting public support (and) to ensure that factions within the LDP continue to support him", Brad Glosserman at Pacific Forum research institute told AFP.

Other analysts said the changes were minor and lowered the chances that Kishida would call an early election this year. 

"(It) turned out that many of the major ministers and LDP executives stayed the same, and it does not look like a 'new look' for Japanese citizens," Shin Sato, associate professor of Japanese politics at Tokyo Metropolitan University, told AFP.

Public support for Kishida has also been hit in recent months by issues including the troubled new "My Number Card" identification system.

There was also a scandal involving "inappropriate behaviour" by Kishida's son, who was removed from his position as his father's secretary this year.

Magazine photos showed guests at a party thrown by Shotaro Kishida pretending to hold a news conference and one lying on red-carpeted stairs.

- 'Rank hypocrisy' -

Five of the 19 ministers in the reshuffled cabinet are women, up from two previously.

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

But Kishida's reshuffle "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", Glosserman said.

"Let's see how long they last."