NATO expects the fighting and the humanitarian emergency in Ukraine to further intensify some two weeks after the start of the Russian invasion on February 24.
"We see with horror the rising numbers of civilian casualties and the senseless destruction by Russian forces. The people of Ukraine are resisting with courage and determination, but the coming days are likely to bring even greater distress," NATO Secretary General Jens Stoltenberg told the Welt am Sonntag newspaper on Sunday.
He called on Russian President Vladimir Putin to "end this war, withdraw all forces and commit to diplomacy."
Stoltenberg dismissed claims by the Russian government that the United States had secretly operated laboratories in Ukraine for the development of biological weapons.
"Now that these false allegations have been made, we must remain vigilant because it is possible that Russia itself could be planning chemical weapons missions under this pack of lies," he said. That would be a war crime.
Stoltenberg again rejected calls for NATO to enforce a no-fly zone over Ukraine. That would mean attacking Russian forces.
"And that would risk a direct confrontation and an uncontrollable escalation. We have to end this war, and not extend it," he stressed.
NATO is a defensive alliance, Stoltenberg said. "We do not seek conflict with Russia," he said.
