Russia's setbacks and stretched resources in Ukraine show its forces are incapable of achieving President Vladimir Putin's initial aims in invading the country as things stand now, the Pentagon's intelligence chief said on Friday.
“We're coming to a point right now where I think Putin is going to have to revise what his objectives are for this operation,” Lt Gen Scott Berrier, director of the Defence Intelligence Agency, told an intelligence and national security conference.
“Because it's pretty clear right now that he's … not going to be able to do what he initially intended to do.”
Mr Putin sent troops into neighbouring Ukraine in February with what US officials say was the objective of unseating Ukraine's western-friendly government.
Ukrainian forces drove Russian fighters from their positions around the capital earlier in the war, and Russia suffered another major setback last week, when a Ukrainian counter-offensive forced its troops back from positions in the north-eastern part of the country.
“The Russians planned for an occupation, not necessarily an invasion, and that has set them back,” Lt Gen Berrier said, citing Mr Putin's reluctance so far to fully mobilise Russian forces to get more manpower into the fight.
US President Joe Biden and other administration officials have taken care not to call Russia's latest retreat a Ukrainian victory or turning point in the war, and analysts caution it is impossible to assess what may lie ahead.
“He’s coming to a decision” point,” Lt Gen Berrier said of Mr Putin. “What that decision will be, we don’t know. But that will largely drive how long this conflict lasts.”
Lt Gen Berrier was speaking at a panel with other senior officials at the intelligence community's Intelligence and National Security Summit at National Harbour in Maryland, right outside Washington.
Asked about concerns that Mr Putin could unleash weapons of mass destruction if he is thwarted on the battlefield by US and Nato-backed Ukrainian forces, CIA Deputy Director David Cohen said: “I don't think we should underestimate Putin's adherence to his original agenda, which was to control Ukraine.
“I don't think we've seen any reason to believe he has moved off that.”
Nor should the US underestimate Mr Putin's “risk appetite”, Mr Cohen said.
Mr Putin and his officials early in the war made allusions to Russia's nuclear arsenal and to massive retaliation in warning Nato not to become involved in the conflict.
“That being said, we have not seen concrete evidence of planning for the use of [weapons of mass destruction],'' Mr Cohen said.
The more probable form of any Russian retaliation against the US would be more attempts at interfering with the country's political system, other security and intelligence officials said.
Separately, in a major regional summit in Uzbekistan on Friday, Mr Putin vowed to press the attack on Ukraine and said that Moscow could ramp up its strikes on the country’s infrastructure if Ukrainian forces attempt to hit facilities in Russia.
The conference included the leaders of China, India, Turkey and several other countries.
Mr Putin said the “liberation” of Ukraine’s entire eastern Donbas region was Russia’s main military goal and that he saw no need to revise it.
“We aren’t in a rush,” the Russian leader said.