Russian forces are positioned and prepared to begin an invasion of Ukraine within 12 hours of the order being given, Nato's top general has said.
General Philip Breedlove, the man in charge of drafting a response to the Russian annexation of Crimea, said yesterday that Russian forces on the border were poised for a three- to five-day operation.
"It's my opinion that they could move within 12 hours of a 'go'," Breedlove said in an interview with CNN. "So essentially they could move right away if given the go."
Breedlove said 40,000 Russian troops remained in border areas, despite reports that Russia had withdrawn some elements of an earlier troop buildup in recent days.
But he added: "40,000 doesn't tell the story. This is a combined arms army with all of the pieces necessary should there be a choice to make an incursion into Ukraine. All of the logistics required in order to successfully make an incursion if they needed [are present]."
Earlier, Breedlove said an invasion could begin in the next three to five days.
Western intelligence agencies have expressed concern at what they have described as worrying troop build-ups on Ukraine's border in the past week. While journalists in the border region have failed to find signs of large troop movements, security sources have said they believe the troops are camouflaged or located on Ministry of Defence land closed to the public.
Sergei Lavrov, Russia's Foreign Minister, has said Russia has no interest in moving troops across the border.
Breedlove's comments come after Nato suspended all military and civilian co-operation with Russia in response to the annexation of Crimea last month. Nato commanders have also been ordered to devise ways to better protect alliance members that feel threatened by Russia.
At a meeting of alliance foreign ministers on Wednesday, Poland asked Nato to station 10,000 troops on its territory.