LONDON (AP) — The British government has introduced new rules aimed at eliminating a gender pay gap that sees men earn almost a fifth more than women.

By April 2018, public- and private-sector companies that employ 250 people or more will have to disclose figures including the median wage for both men and women and the overall gender pay gap. Firms are also supposed to produce a plan to narrow the gap.

The first figures were published Thursday.

The government says Britain's pay gap is a record-low 18.1 percent, but should be eliminated altogether.

Britain says it is one of the first countries to introduce mandatory pay-gap reporting. It does not go as far as Iceland, which plans to make employers prove they offer equal pay regardless of gender, ethnicity, sexuality or nationality.