Ukrainians fleeing into central European countries pleaded for Western nations to take tougher steps against Russia following Moscow's invasion that has created nearly 1.5 million refugees.

At the Medyka crossing, Poland's busiest, along its roughly 500 kilometer (310 mile) border with Ukraine, refugees called for a no-fly zone over Ukraine — something NATO powers have so far ruled out on the grounds that it would risk escalating the conflict beyond Ukraine.

"Please close the sky," said Solomiya Zdryko, 18, who fled from Lviv in western Ukraine. "I know that it's not possible for us to join NATO but at least close the sky because people are dying."