Polish President Andrzej Duda on Tuesday said his country would not send military planes to Ukraine since it would be seen as "military interference".
Duda was speaking alongside NATO chief Jens Stoltenberg during a visit to Poland's Lask airbase.
"We are not sending our planes because that would mean military interference in the conflict," Duda said when asked if Poland would send planes as well as the arms and ammunition it has already dispatched.
"NATO is not a party to this conflict," he said.
The Western military alliance has for the first time deployed part of its response force to Eastern Europe to respond to mounting concern over Russia's invasion of Ukraine in the formerly Moscow-dominated region.
During his visit on Tuesday, Stoltenberg said that NATO "is not going to send troops into Ukraine or move planes into Ukrainian airspace".
Seperately Polish Prime Minister Mateusz Morawiecki said that Russia's invasion of Ukraine is an existential threat to peace in Europe.
Ukraine has received weapons shipments from NATO members to help withstand a military invasion unleashed by Russian forces last week, while the West has also introduced sweeping sanctions on the Russian economy.
"Today we focus on the situation in Ukraine, because it is an existential threat to peace in Europe," Morawiecki said after a meeting with European Commission head Ursula von der Leyen in Brussels.
He said Poland wanted the strongest possible sanctions to be introduced against Russia, including a ban on the import of coal.
"I can declare we can introduce an embargo on Russian coal even tomorrow. We are ready for that, we just want to get the fastest possible consent from the European Commission," Morawiecki said, also calling for Europe to stop buying Russian gas and oil "in a perspective of months".
He also told reporters Poland proposed that sanctions should be imposed on Russia's ally, Belarus, as soon as possible and said the head of the Commission agreed with him.
