Ukrainian prime minister Arseny Yatseniuk said his government would ask parliament to abandon Ukraine's non-aligned status and set the country on course to seek to become a member of Nato.
He added that the basic aim of Ukrainian foreign policy remained to become a member of the European Union.
Ukrainian troops are locked in a five-month conflict with Russian-backed separatist rebels.
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.