Russia demanded on Thursday that the Ukrainian government stop its military operation against pro-Russian separatists and urged the United States and European Union to press Kiev to avert a “catastrophe” in the former Soviet republic. “We once again demand that the Kiev authorities stop the fratricidal war and start a real national dialogue with all political forces and representatives of the country’s regions,” the Russian Foreign Ministry said in a statement. The Ukrainian government and President-elect Petro Poroshenko have defied Moscow’s calls for an end to the operation against the rebels in eastern Ukraine, where casualties on both sides have been heavy this week. More