David Cameron issues aid challenge to rich nations

David Cameron has called on wealthier countries to match the UK's commitment to devoting at least 0.7% of national wealth to foreign aid.

The prime minister has been addressing a UN session in New York marking the 17 new Sustainable Development Goals.

"Aid is not enough on its own. Of course not. But it is essential. And it works,'' he said.

"So today, I call on others to follow Britain's lead. I say to my fellow world leaders from developed countries: we've been making these aid promises for years. Now, let us all deliver on them.''

"The world is watching."