Angelina Jolie-Pitt has said that countries have neglected their international responsibilities to refugees in a speech on the global refugee crisis.

The Special Envoy to the United Nations High Commissioner for Refugees (UNHCR) was speaking as part of the BBC's World On The Move special, a day of live coverage looking at global migration and how it is changing the world.

In her impassioned speech, she said that fear of uncontrolled migration had legitimised people who promote a "politics of fear and separation", creating a "race to the bottom" where countries neglect their responsibilities.

She highlighted the fact that the average refugee remains a refugee for 20 years, and said that the scale of the crisis was unprecedented, with many refugees not being able to return home.

Mrs Jolie-Pitt called for every country to do its fair share and not "abdicate responsibility", saying that now was a "once-in-a-generation" opportunity for nations to pull together and solve the international crisis.

"The worst possible choice you could make is to decide to step back from the world," she said.

"Isolationism is not strength. Fragmentation is not the answer."