Germany's Angela Merkel warned Moscow ahead of talks on Ukraine on Wednesday that economic sanctions remained an option unless it backed peace efforts, as Ukrainian government forces pressed on with an offensive against pro-Russian rebels.
The Ukrainian, Russian, German and French foreign ministers were due to meet in Berlin at 4.30 p.m. (1430 GMT) to discuss restoring a 10-day ceasefire in eastern Ukraine, which the chancellor said had prompted "no significant reaction" from the separatists.
"We will not stop looking for diplomatic solutions," Merkel said. "But we are nowhere near where we want to be."
"Regarding sanctions against Russia, we have so far reached level two and we cannot rule out having to go further," Merkel said, referring to measures against Russian officials and firms the West accuses of undermining Ukraine's territorial integrity.
The European Union and United States have threatened to ratchet up sanctions against the Russian economy unless it reins in the separatists in eastern Ukraine. Moscow denies supporting them.