World leaders are gathering 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.
Twenty-four sailors were arrested in the Black Sea incident.
A massive security operation is under way for the summit in the Argentine capital, Buenos Aires.
A bank holiday has been declared for Friday and the city’s main business district has been shut down.
