The US, the European Union and Nato should arm Ukraine in its effort to repel a "Russian invasion," according to the chairman of the US senate's foreign relations committee.
Democratic senator Robert Menendez told CNN's State of the Union programme: "This is a direct invasion by Russia. It's not rebels, it's Russian soldiers."
He added that the US, EU and Nato "should be providing the Ukrainians with the types of defensive weapons that will impose a cost upon (Russian President Vladimir) Putin for further aggression."
Asked whether President Obama's administration is considering such a move, he said: "I think that may very well be on the table right now. These are changed circumstances."
Were the Russians -as Barack Obama claims - weighed down by sanctions, or where the Ukrainians looking to cut their losses?
The new president of the European Council could be "very important" for David Cameron.