Western Leaders Scramble to Calm Conflict in Ukraine

Moscow Warns Any Military Aid Will Be Seen as Threat to Russian Security.

The diplomatic scramble to calm the conflict in eastern Ukraine entered a new, urgent phase Thursday as Western leaders descended on Kiev, while Moscow warned that any military aid to the country would be seen as a threat to Russian security.

U.S. Secretary of State John Kerry met Ukrainian President Petro Poroshenko in Kiev and repeated Western demands that Russian-backed separatists pull back their fighters and arms.

German Chancellor Angela Merkel and French President François Hollande were due to arrive later in the day on an emergency trip of their own, and to travel to Moscow to meet with Russian President Vladimir Putin on Friday.

“We are hopeful Russia will take advantage of a broad-based acceptance that there’s a diplomatic resolution staring everybody in the face,” Mr. Kerry said in Kiev.

The rapid-fire diplomacy comes amid a rise in violence between Ukrainian forces and Russian-backed separatists that Western officials fear could draw Russia and Ukraine into a fully-fledged war. Battlefield gains by the rebels appear to have spurred Mr. Putin to push for more concessions, spelled out in a Kremlin proposal sent to Paris and Berlin in recent days and described by Western diplomats. Meanwhile, the military setbacks for Kiev have led Washington to reconsider its earlier opposition to weapons aid to Ukraine, although Germany and other key European countries still oppose such a move.

More From The Wall Street Journal (subscription required):