Nato: No doubt Russia working to destablise Ukraine

The head of Nato told ITV News he is in no doubt that Russia is conducting a secret military operation to destabilise eastern Ukraine, calling it a "kind of hybrid warfare" involving undercover forces.

Ukraine's government is still fighting to regain towns and cities in the East from Russian-backed separatists.

Read: Ukraine president drops ceasefire against 'terrorist' rebels

Anders Rasmussen said it was essential the the US military stay fully committed to Europe, as James Mates reports.