Russia on Monday said it will deliver gas to Ukraine only if it is paid in advance, accusing its western neighbour of "chronic non-payment," dpa reported. "Today at 10 am Moscow time (0600 GMT) Gazprom in full accordance with contractual obligations, switched to pre-payment gas deliveries for Naftogaz Ukraine," the company said in a statement. Russia had given cash-strapped Ukraine until 0600 GMT Monday to settle about 2 billion dollars in gas arrears. The two countries held last-minute talks late Sunday in Kiev on their gas-pricing dispute, but the meeting ended after several hours with no apparent agreement. EU Energy Commissioner Guenther Oettinger, who mediated the talks, put forward a proposal that would involve Ukraine paying 1 billion dollars on Monday and the remanding unpaid bills in six installments, the EU Commission said. "The Ukrainian side was ready to accept this, but for the moment the Russian partners were not," the Commission said in a late-night statement. Ukraine is a key transit route for energy flows to Western Europe, and any halt in supplies would affect several EU member states dependent on Russian gas.