Poland’s foreign minister has sparked fresh controversy and intense discussion within the NATO military alliance by saying that member states have a ‘duty’ to shoot down incoming Russian missiles when they are in Ukraine’s skies threatening the population below.

“Membership in Nato does not trump each country’s responsibility for the protection of its own airspace – it’s our own constitutional duty,” Foreign Minister Radosław Sikorski told the Financial Times. The comments appeared to shirk off the possibility that such action risks major escalation with Russia.

“I’m personally of the view that, when hostile missiles are on course of entering our airspace, it would be legitimate self-defense [to strike them] because once they do cross into our airspace, the risk of debris injuring someone is significant,” the Polish top diplomat said.