Czech president Petr Pavel has warned that NATO must be ready to respond firmly to Russian airspace violations, even if that means shooting down their planes.
Mr Pavel said the organisation should act decisively to stop any breach of allied skies and make clear there are consequences for crossing the line.
He said: 'Russia will realise very quickly that they have made a mistake and crossed the acceptable boundaries. Unfortunately, this is teetering on the edge of conflict, but giving in to evil is simply not an option.'
It comes as the UN's Security Council will meet on Monday for emergency talks after Vladimir Putin's fighter jets flew into NATO-member Estonia's airspace, raising fears of World War Three.
Estonia announced on Sunday that the emergency session had been called 'in response to Russia's brazen violation of Estonian airspace.'
