Russia's invasion of Ukraine is encountering "stiffer than expected" resistance from the Ukrainian military as well as unexpected difficulties supplying its forces, two senior US officials with direct knowledge tell CNN.
On the battlefield, Russia is suffering heavier losses in personnel, armor and aircraft than expected. This is due, in part, to the fact Ukrainian air defenses have performed better than anticipated in pre-invasion US intelligence assessments. In addition, Russia has yet to establish air supremacy over Ukraine, a senior defense official said, as the Ukrainian Air Force and air defense systems fight for control of the airspace.
Ukrainian air defenses, including aircraft, do continue to be operable and continue to engage and deny access to Russian aircraft in places over the country,” the official said.
Without uncontested control of the skies, it becomes more difficult for an army on the move to see and strike targets from the air.
Officials caution this picture of the battlefield is just a moment in time, and the situation on the ground could change very quickly as Russian forces keep up their assault.
The Ukrainian military has a number of different anti-aircraft weapons, including radar-guided and heat-seeking missiles, as well as anti-aircraft guns, according to IHS Janes. The US has also provided Stinger anti-aircraft missiles in recent weeks, as have other NATO allies.
As of Saturday evening, the US had not seen any indication the Russian military has taken control over any Ukrainian cities, the official said, even as Russian forces have moved to surround some population centers, including the capital of Kyiv.
Keeping Russia's large invasion force supplied with fuel and ammunition has also proven difficult. As one senior US official explained, Russia anticipated a fast victory and may have neglected to plan for sufficient resupply. Supply lines, this official explained, are a "definite vulnerability."
What we assess now is that [Russia] had to commit a bit more logistics and sustainment, in fuel specifically, than what we believe they had planned to do this early in the operation,” said one of the officials.��
Together, these challenges have thus far prevented the quick overthrow of major Ukrainian cities including Kyiv, which US officials were concerned could play out in a matter of days. The city of Kharkiv near Ukraine’s border with Russia also has not fallen to invading forces, which officials worried could happen on the invasion's first night.
These officials caution, however, Russian forces still greatly outnumber Ukrainian forces and Russia continues to maneuver these forces into position around major urban centers. It’s also unclear how much of the slower movement can be attributed to the logistical challenge of moving such a large force.
Russia has spun its slow advance in Ukraine as a stop to allow time for negotiations, not a military setback.
On Saturday, the Russian Ministry of Defense said its troops have been ordered to resume their offensive “in all directions,” after a suspension was ordered for negotiations with the Ukrainian government. The ministry said the offensive was ordered to continue after Ukraine abandoned the consultations.
A Ukrainian presidential adviser denied in the early hours Saturday that Ukraine had refused to negotiate.
“They are having problems,” a NATO official explained, pointing to the alliance’s latest intelligence. “They lack diesel, they are proceeding way too slow and morale is obviously an issue.”
Asked whether Russians are likely to intensify their efforts, the official said they have no choice.
“They are way behind schedule,” he said. “This is getting out of hand for them, every additional day is very painful.”