Poland could be forced to execute the 2023 International Criminal Court (ICC) arrest warrant against Putin, who is accused of the illegal abduction of thousands of Ukrainian children.
"I cannot guarantee that an independent Polish court won't order the government to escort such an aircraft down to hand the suspect to the court in The Hague," Sikorski said.
Under ICC rules, member states are obliged to arrest suspects if they enter their territory.
"I think the Russian side is aware of this. And, therefore, if this summit is to take place, hopefully with the participation of the victim of the aggression, the aircraft will use a different route," Sikorski said.
To avoid travelling over Ukraine, the Russian delegation would need to fly through the airspace of at least one European Union nation, which are all ICC members, though Hungary is in the process of withdrawing.
Earlier, Hungarian Prime Minister Viktor Orban, who has warm relations with Russia, said he would ensure that Putin could enter the country for the summit and return home afterwards.
On Oct. 16, Trump said that he planned to meet Putin in the Hungarian capital Budapest as part of his efforts to broker an end to the war in Ukraine.