Japan's annual birth rate has dipped below one million for the first time in over 100 years - reflecting a fast-ageing society.

The total number of births is expected to be between 980,000 and 990,000 this year, down from slightly more than one million last year.

Figures have never fallen below the million since data became available in 1899.

The latest statistics were reported by Kyodo news agency based on unidentified government sources.

The number of women in their twenties in Japan is falling Credit: Reuters

Among the key factors in the falling number of births is the shrinking population of women in their 20s and 30s - down roughly 20% than a decade ago.

Japan's fertility rate was 1.45 in 2015, up 0.03 points from a year earlier, helped by an economic recovery, and is recovering from the record low of 1.26 hit in 2005.

However, it is still far from the government's goal of 1.80.

On Thursday, Japan's cabinet approved a record £670 billion spending budget for 2017, which includes child-rearing support.

The health ministry plans to release its estimate of the number of this year's births this week.