If you needed further evidence of the pressure that US President Barack Obama is under to send arms to the Ukrainian government, just listen to my interview with Senator Joe Manchin.

He spoke to me as Russian, Ukrainian, German and French leaders were meeting in Minsk to discuss a truce between Russia and Ukraine.

The Democrat from West Virginia echoes the argument of those who say the US must support an ally that is pro-Western.

While agreeing that a military solution was unlikely, Senator Manchin sees American weapons as a deterrent - a way to force Russia to realise that the costs of meddling in Ukraine are serious.

He holds out little hope, by the way, for the Minsk talks.