Ryanair CEO Michael O’Leary has warned that Russian drone incursions into European airspace, like the recent incident in Poland, will remain a persistent challenge for airlines in the coming years.

“This will be a permanent problem for all airlines over the next few years,” O’Leary told Bloomberg, adding that Europe must deliver a strong response to such threats from Russia.

The recent drone incursion into Polish airspace, which occurred during a large-scale Russian attack on Ukraine, forced authorities to temporarily close parts of Poland’s skies. The disruption led to widespread flight delays across Scandinavia, the Baltics, and Germany, with Ryanair’s on-time performance dropping to just 60%.

Polish Prime Minister Donald Tusk confirmed that 19 Russian drones entered Polish territory, four of which were shot down. Several drones reportedly crossed into Poland from Belarus.

O’Leary said the incident should be seen as a “wake-up call for Europe and NATO,” warning that further disruptions are likely unless the EU and the White House take decisive action, including imposing additional sanctions on Russia.