Poland warned Russia's President Vladimir Putin on Tuesday against travelling through its airspace for a summit in Hungary with U.S. President Donald Trump, saying it could be forced to execute an international arrest warrant if he did, Reuters reported.

Bulgaria, however, would be willing to let Putin use its airspace if the summit is held in Hungary, Foreign Minister Georg Georgiev was quoted as saying.

Trump said last week he planned to meet Putin in Budapest as he tries to broker an end to Russia's war in Ukraine, according to Reuters.