Leaders Gather at G20 Summit

World leaders are meeting in Argentina for their annual G20 summit amid new tension with Russia over Ukraine and a US trade row with China.

US President Donald Trump has cancelled a meeting with his Russian counterpart, Vladimir Putin, in protest at Russia's seizure of Ukrainian naval boats.

Also on the programme: World Aids Day is tomorrow but how much closer is a vaccine or a cure; and we look at The Wizard of Oz after Italian researchers hail it the most influential film of all time.

(Photo: Xi Jinping and Donald Trump, Credit: Getty Images)