'Very Clear Message' Sent To Russia At G20 David Cameron has said that a "very clear message" has been sent to Vladimir Putin, after the Russian president left the G20 summit in Australia early. Mr Putin cut short his appearance at the meeting of world leaders after pressure over the crisis in eastern Ukraine, where pro-Russia rebels have been fighting Ukrainian forces. The Prime Minister said "further measures" would follow against Russia if it continues to destabilise Ukraine. Vladimir Putin was confronted by David Cameron over the Ukraine crisis Mr Cameron also said the summit in Brisbane had sent a message to Russia to stop meddling in Ukraine or risk more sanctions. He added: "I think what has been good about this G20 is that a very clear message has been delivered by the countries of the European Union and America to Russia about how we're going to approach this in the months and years ahead." Video: PM On Message To Russia At G20 On Saturday, Mr Cameron confronted Mr Putin on the fringes of the summit over Moscow's interference in Ukraine. Soon after Mr Cameron spoke, US president Barack Obama said: "At this point the sanctions we have in place are biting plenty good. We retain the capability, and we have our teams constantly looking at mechanisms in which to turn up additional pressure as necessary. Video: Obama On Further Russia Sanctions The US and the EU have had a series of sanctions placed on Russia and figures close to Mr Putin for several months. During a news conference before he left, Mr Putin praised the "constructive atmosphere" of the summit in Australia, despite his decision to leave early. He said: "Some of our views do not coincide, but the discussions were complete, constructive and very helpful." Video: Australian PM Hits Out At Russia His decision to leave Brisbane before the leaders' lunch on Sunday came after world leaders criticised Mr Putin for Russia's role in the conflict in Ukraine. He told a media conference that he was leaving early because it was a long way home and he needed to get some sleep. Mr Cameron had warned Mr Putin that Moscow needs to implement a peace deal designed to de-escalate Ukraine's crisis or future relations with the West are threatened. Mr Obama said Moscow's "aggression against Ukraine" was "a threat to the world." Canadian Prime Minister Stephen Harper also had a blunt message for Mr Putin, saying: "I'll shake your hand, but I only have one thing to say to you: you need to get out of Ukraine." Video: Putin Receives Criticism At G20 The summit has been dominated by tensions over Moscow's actions, with world leaders consistently voicing their opposition to the destabilisation of Ukraine. Ahead of the summit, Mr Putin stoked tension in Brisbane by deploying four Russian warships to the Coral Sea off Australia's eastern coast.