Russian forces' movement towards the Ukrainian capital city of Kyiv is currently "stalled," a senior U.S. defense official said Tuesday morning, citing a variety of factors, including a lack of food for Russian troops.

With Russia having committed now more than 80% of their assembled combat power, they have made little substantial movement toward Kyiv in the past 24 hours, the official said.

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"It doesn’t appear to be making a lot of progress," the official said, discussing the movement on the capital.

This satellite image provided by Maxar Technologies shows the southern end of a convoy, east of Antonov airport, Ukraine, Monday Feb. 28, 2022. 

This satellite image provided by Maxar Technologies shows the southern end of a convoy, east of Antonov airport, Ukraine, Monday Feb. 28, 2022.  (Satellite image ©2022 Maxar Technologies via AP)

The official said in explaining the Russian's lack of progress, while "some of it has to do with their own sustainment and logistics," some of it is also due to the Ukrainian resistance. 

The official said that the U.S. has observed that there are "some morale problems" in some parts of the Russian military, as they face not just fuel and food problems, but greater resistance than anticipated. 

Smoke rising after shelling on the outskirts of the city is pictured from central Kyiv, Ukraine February 27, 2022. REUTERS/Irakli Gedenidze

Smoke rising after shelling on the outskirts of the city is pictured from central Kyiv, Ukraine Feb. 27, 2022.  (REUTERS/Irakli Gedenidze)

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A significant number of Russian troops in Ukraine are conscripts, typically young men without much training or knowledge when it comes to combat operations. The official could not confirm reports that any Russian troops have defected, or that any have intentionally run out of gas.

The UK Ministry of Defence published a map of its understanding of Russian attacks and troops locations as of March 3, 2022. 

The UK Ministry of Defence published a map of its understanding of Russian attacks and troops locations as of March 3, 2022.  (UK Ministry of Defence)

The official noted that Russia's current lack of progress may not be only due to problems arising from resistance or their own logistics, and they are "possibly regrouping, rethinking, reevaluating" before carrying on again.

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Discussing weapons capabilities, the official could not confirm reports that Russia was utilizing cluster munitions, although the U.S. had seen video footage meant to support such a claim. What the official did say was that Russia has "launcher systems that could be used for a thermobaric weapon," although they could not confirm the use or presence of such a weapon.

More than 80% of the pre-staged Russian combat power is now inside Ukraine, up from less than 75% on Monday, the official said. Russia has made gains in the southern part of Ukraine and is currently occupying the cities of Malitopol and Berdyansk, according to the official.