US top diplomat Antony Blinken warned Wednesday that the deployment of North Korean troops alongside Russian forces fighting on the Ukrainian border demanded a “firm response”. The secretary of state was speaking at the start of a day of Brussels talks with NATO and EU officials to urgently address ramping up support for Kyiv before Donald Trump reclaims the White House — potentially jeopardising future aid. Addressing reporters alongside NATO chief Mark Rutte, Blinken said they had discussed the fact North Korean forces have been “injected into the battle, and now, quite literally, in combat which demands and will get a firm response.”