He says this in a meeting with Ukraine's president Volodymyr Zelenskyj in New York.
Trump replied "Yes, I do", when he was asked if he thought that NATO countries should act more resolutely and shoot at the planes, after the recent violations in among other things Estonia.
Germany's Minister of Defence Boris Pistorius warned earlier on Tuesday that Russia with its violations is trying to catch NATO in an "escalation trap".
Keeping a cool head is not to be cowardly and afraid, but to show responsibility towards one's country and peace in Europe, he said at a press conference in Berlin together with Sweden's Minister of Defence Pål Jonson (The Moderate Party).
