Ukrainian President Volodymyr Zelenskiy had appealed to Nato to declare a no-fly zone over his country, which Russian forces invaded by land, sea and air on 24 February.
"We are not part of this conflict," Nato Secretary General Jens Stoltenberg said in denying Ukraine's request.
"We have a responsibility as Nato allies to prevent this war from escalating beyond Ukraine because that would be even more dangerous, more devastating and would cause even more human suffering," he said following a Nato meeting in Brussels.
