G20 Summit: David Cameron and Tony Abbot arrive in Australia British Prime Minister David Cameron and his Australian counterpart Tony Abbott have arrived in Brisbane for the G20 leaders’ summit, where the crisis in Ukraine is expected to take centre stage. The summit, which begins tomorrow, promises to be a showdown between Western leaders and Russian President Vladimir Putin, amid fresh reports of Russian troops pouring into eastern Ukraine. At a news conference in Canberra today, Mr. Cameron criticised Russia's actions, warning they could draw greater sanctions from the United States and the European Union. Russia however denies sending troops and tanks into Ukraine. BBC