A convoy of Russian military vehicles has moved less than 15 miles outside of Kyiv over several days as Russian President Vladimir Putin plans to take over Ukraine's government.
A U.S. defense official said during a Wednesday briefing that Russia is currently using about 82% of its full staged combat power in Ukraine, which he added is "not a significant influx of additional combat capability into Ukraine from what was staged over the last few months."
"We believe that the convoy is stalled. It's a long convoy," the official said. "…Again, we don't have perfect visibility into what's going on on the ground there, but we believe that there's numerous factors for this one. The Ukrainians have been conducting a stiff resistance north of Kyiv. And we have some indications that they have also at places and at times tried to target this convoy."
The official added later: "[W]e would say that there essentially has been no movement closer to the city than what we briefed a couple of days ago. I say appreciable movement because we don't have perfect visibility on every unit, every tank, every truck, but basically, they remain stalled outside the city center in Kyiv."
A U.S. official said on Tuesday 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.
UKRAINE INVASION: RUSSIAN TROOPS STALLED NORTH OF KYIV, RUNNING OUT OF GAS AND FOOD, OFFICIALS SAY
Despite the slow movement of the convoy, however, officials have observed an increase in Russian artillery and missiles striking the city.
Kyiv and Kharkiv are "continually under assault," but with no "appreciable movement by the Russians to take" control of those areas. Convoys outside of the two cities "appear to be stalled" and are being met "with resistance," the official said Wednesday.
Ukrainian President Volodymyr Zelenskyy has said he will be Putin's first target once the convoy enters Kyiv, but he has refused offers from the U.S. to evacuate, insisting instead on staying in the country's capital to help its residence fight off Russian forces.
In southern cities such as Mariupol, however, Russia is making more progressive advances, according to the official, who said the general assumption is that Russia's "approach on Mariupol will be from multiple directions with what could likely be an attempt to encircle the city."
The southern Ukrainian city of Kherson, a strategically important city located near the Black Sea, has fallen to Russian forces, becoming the first major city to fall since Russia launched its invasion of Ukraine last week.
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"There is no Ukrainian army here," Kherson Mayor Igor Kolykhaev said Wednesday, according to The New York Times. "The city is surrounded."
Kolykhaev said that Ukrainian forces have pulled out of the city and relocated to the area of Mykolaiv, a city northwest of Kherson.
Fox News' Ronn Blitzer and Michael Lee contributed to this report.