Ukraine war latest: Russia admits its armed forces have suffered casualties

The Pentagon said it had “no reason to doubt” reports that Putin had placed his nuclear forces on high alert.

“This is not only an unnecessary step for him [Putin] to take but an escalatory one,” said a senior US defence official. “It is clearly potentially putting at play forces that if there’s a miscalculation could make things much more dangerous.”

The Pentagon declined to say if it had altered its nuclear posture in response to the move by Putin.

“We do not talk about specifics of our strategic deterrent posture,” the official said. “We remain confident in our ability to defend ourselves and our allies and our partners, and that includes in the strategic deterrent realm.”

Separately, White House press secretary Jen Psaki said of the move: “This is really a pattern that we’ve seen from President Putin through the course of this conflict, which is manufacturing threats that don’t exist in order to justify further aggression.

“At no point has Russia been under threat from Nato, has Russia been under threat from Ukraine, this is all a pattern from President Putin . . . we have the ability to defend ourselves, but we also need to call out what we’re seeing here,” she told ABC on Sunday.

A senior US defence official said that the Russian military had moved large numbers of forces into Ukraine over the past 24 hours. He said Russia has now deployed two-thirds of the combat forces it had amassed on the border before the invasion — an estimated total of 150,000 troops — into Ukraine. Russian forces remained 30km from the centre of Kyiv, an unchanged from an assessment on Saturday.

The official said Russia had launched roughly 320 missiles this week, but that it had experienced some launch failures. Russia had not yet achieved air domination over Ukraine, where air and missile defences remained intact.

“The Ukrainians are putting up a stiff resistance,” he said. “But the Russians have still have a lot of operational advantages despite the shortcomings they’ve had with logistics and sustainment and in some of their manoeuvres. They still have an awful lot of combat power that is viable and arrayed in and outside Ukraine.”