Russia's state-run natural gas monopoly Gazprom has warned Ukraine that it will reduce supplies to that country if Kyiv fails to pay more than $1 billion it owes by the end of the month. A Gazprom statement says Russia has fully complied with its contract on deliveries to Ukraine. But it says that country's debt has topped $1.3 billion. The firm says it has informed its European clients of the problem. In Brussels, the European Commission urged a speedy settlement of the issue.