Vladimir Putin leaves G20 after leaders line up to browbeat him over Ukraine Russian President Vladimir Putin departs Brisbane, Australia, on Sunday before the formal end of the two-day G20 summit Vladimir Putin quit the G20 summit in Brisbane early saying he needed to get back to work in Moscow on Monday after enduring hours of browbeating by a succession of Western leaders urging him to drop his support for secessionists in eastern Ukraine. With the European Union poised this week to extend the list of people subject to asset freezes, the Russian president individually met five European leaders including the British prime minister, David Cameron, and the German chancellor, Angela Merkel, where he refused to give ground. Putin instead accused the Kiev government of a mistaken economic blockade against the cities in eastern Ukraine that have declared independence in votes organised in the past month. He said that action was short-sighted pointing out that Russia continued to pay the salaries and pensions of Chechenya throughout its battle for independence. Justifying his early departure Putin said: "It will take nine hours to fly to Vladivostok and another eight hours to get Moscow. I need four hours sleep before I get back to work on Monday. We have completed our business. In an interview with German TV he also accused the west of switching off their brains by imposing sanctions that could backfire. Putin said: "Do they want to bankrupt our banks? In that case they will bankrupt Ukraine. Have they thought about what they are doing at all or not? Or has politics blinded them? As we know eyes constitute a peripheral part of brain. Was something switched off in their brains? The Russian leader also complained he had not been consulted by the EU about the recognition of Ukraine. However, British officials insisted behind Putin's bluster, that they detected a new flexibility about the Ukraine orientating towards the EU so long as this did not extend to Nato assets being placed on Ukrainian soil. Putin spent as long as eight hours on the margins of the summit holding separate talks with Western leaders including a marathon session with Merkel that did not wrap up until 2am. The Merkel negotiations preceded a meeting on Saturday between EU leaders and the US president, Barack Obama, which was called to discuss next steps in Ukraine and world trade. Cameron said a resolution might take time but at least Putin had acknowledged that Ukraine was a single political space. In his own press conference, Cameron said: "This is going to be a test of the stamina political will of the United States and the EU. I think we will meet that test. We are very clear with Russia that the continued destabilisation of Ukraine is simply unacceptable. If Russia continues to destabilise Ukraine there will be further sanctions. There is a cost to sanctions, but there would be a far greater cost to allow a frozen conflict on the continent of Europe to be maintained. President Putin can see he is at a crossroads. Obama said his recent discussions with the Russian president, at Apec and at the G20, had been "typical of our interactions: businesslike and blunt." He said Russia had failed, in spirit and letter, to adhere to the Minsk agreement signed in September, and that while the US was not actively considering further sanctions on Russia, it would consider increasing the pressure on Moscow if Russia's intransigence continued. "At this point, the sanctions that we have in place are biting plenty good," he said. Obama said Russia had the "opportunity to take a different path" to escalating the conflict, and that if Putin chose to seek a diplomatic solution the US would be the first country to suggest rolling back the current sanctions "that are frankly having a devastating effect on the Russian economy." But Russia would remain isolated, Obama said, if it continued to violate international law and to fund and arm rebels fighting its proxy war inside Ukrainian territory. It is not our preference to see Russia isolated the way it is. We would prefer a Russia that is fully integrated in the world economy, that is thriving on behalf of its people, that can once again engage with us. The crisis has been deepened by the creation of the declared Donetsk People's Republic (DNR) led by Alexander Zakharchenko, an electrician turned battalion commander. Earlier this month the region occupied by separatists for six months organised an unauthorised vote to appoint a prime minister. The Ukrainian prime minister, Arseniy Yatsenyuk, announced in response that all state funding would be cut off, arguing that the elections violated the Minsk peace accords signed in September. Nato claims 300 Russian troops remain in Ukraine training the separatist forces ahead of likely fresh offensives. Several of the contested areas are crucial for the republic's long-term survival, including the port city of Mariupol and a power station north of Luhansk. The two provinces in Donetsk and Luhansk normally account for 16% of Ukraine's GDP, supply 95% of its coal and produce a disproportionate share of exports. Although Putin has admitted the sectoral sanctions are hitting his economy, the Ukrainian economy is also pressure. From now until the end of 2016 about $14bn of debts denominated in foreign currencies are due. Ukraine must also pay $700m a month for gas imports from Russia. Its foreign-exchange reserves have probably dwindled to about $12bn. Putin has insisted he will not cut funding to Ukraine, or demand early repayment of loans. We do not want to aggravate the situation. We want Ukraine to get back on its feet at last," the president has previously said. Although the western media has portrayed Putin as an isolated figure at the summit, he has continued to forge close relations with the Brics countries (Brazil, Russia, India, China and South Africa) a grouping that is becoming increasingly organised at the G20 and, in terms of economic size, more than matches the size of the G7 economies.