Japan should fix its shrinking workforce by enabling women to work, before turning to the "Pandora's box" of immigration, the country's minister for the empowerment of women said in an interview last week.

Haruko Arimura, a 44-year-old mother of two, said Japan must act fast to change a trend that could otherwise see the workforce decline by almost half by 2060. But she warned if immigrants were mistreated — something she'd witnessed overseas — it raised the risk of creating resentment in their ranks.

"Many developed countries have experienced immigration," she said in her Tokyo office. "The world has been shaken by immigrants who come into contact with extremist thinking like that of ISIL, bundle themselves in explosives and kill people indiscriminately in the country where they were brought up," Arimura said, using one of the acronyms for Islamic State.