GENEVA (AFP) - High-stakes talks bringing together Russia, Ukraine, the United States and the European Union kicked off in Geneva on Thursday in a bid to ease the worsening crisis in the former Soviet republic.

Russian Foreign Minister Sergei Lavrov, Ukrainian counterpart Andriy Deshchytsya, US Secretary of State John Kerry and EU foreign policy chief Catherine Ashton sat down at the negotiating table, just hours after three pro-Moscow separatists were killed in Ukraine's south-east during a raid on a military base, ratcheting up tensions.