British Ambassador's statement at UN

British Foreign & Commonwealth Office spell it out:

"There are three things that now need to happen to prevent further escalation [of the conflict in Eastern Ukraine].

First, Russia must immediately withdraw its military forces from Ukraine, stop its flow of weapons to the separatists, and make every effort to secure a political solution to this crisis. This includes the immediate release of Nadiya Savchenko, who has been illegally detained for nearly a year. 

Second, we urge Russia to use its considerable influence on the separatists to cease their provocative behaviour and live up to their commitment to implement fully the Minsk Agreements. The separatist forces are Russia’s creation; they are Russia’s tool. Russia has the capacity and the influence to control the separatist forces. It must exercise that influence to ensure compliance with the Minsk agreements. If it is not ready to do so, this Council must be clear in its condemnation.

And third, it is vital that all parties engage seriously in the process and implement the Minsk agreements..."