China has announced that it will allow couples to have up to three children, after census data showed a steep decline in birth rates.

China scrapped its decades-old one-child policy in 2016, replacing it with a two-child limit which has failed to lead to a sustained upsurge in births.

The latest move was approved by President Xi Jinping in a politburo meeting, state media said.

It will come with "supportive measures, which will be conducive to improving our country's population structure, fulfilling the country's strategy of actively coping with an ageing population and maintaining the advantage, endowment of human resources", Xinhua said.