The US ambassador to the United Nations has got into a harsh war of words with her Russian counterpart.

Samantha Power criticised Russia for calling an emergency meeting after the US mistakenly bombed Syrian government troops. She called the move a "stunt", and Russia's UN ambassador called her words "demagoguery of the highest order".

Ms Power spoke to the BBC's Laura Trevelyan in advance of the UN's Refugee Summit, which will be hosted by US President Barack Obama.