The Pentagon said it had “no reason to doubt” reports that Putin had placed his nuclear forces on high alert.
“It’s not just an unnecessary step for him [Putin] to take but an escalation,” said a senior US defense official. “It’s clearly potentially bringing forces into play which, if miscalculated, could make things much more dangerous.”
The Pentagon declined to say whether it changed its nuclear stance in response to Putin’s decision.
“We don’t talk about the details of our strategic deterrence posture,” the official said. “We remain confident in our ability to defend ourselves and our allies and partners, and that includes in the area of strategic deterrence.”
Separately, White House press secretary Jen Psaki said of the decision, “It’s really a pattern that we’ve seen from President Putin throughout this conflict, who manufactures threats that do not exist in order to justify further attacks.
“At no time has Russia been threatened by NATO, Russia has not been threatened by Ukraine, this is all a pattern of President Putin…we have the ability to defend ourselves, but we have to also say what we see here,” she told ABC on Sunday.
A senior US defense official said the Russian military had moved a large number of forces into Ukraine over the past 24 hours. He said Russia has now deployed two-thirds of the combat forces it amassed on the border before the invasion – an estimated total of 150,000 troops – to Ukraine. Russian forces remained 30 km from central Kiev, unchanged from Saturday’s assessment.
The official said Russia had launched about 320 missiles this week, but had experienced a few launch failures. Russia had yet to achieve air dominance over Ukraine, where air and missile defenses remained intact.
“The Ukrainians are putting up fierce resistance,” he said. “But the Russians still have a lot of operational advantages despite the shortcomings they had in logistics and sustainment and in some of their maneuvers. They still have a tremendous amount of combat power that is viable and deployed inside and outside Ukraine.