Russia is making "incremental gains" in Ukraine’s eastern Donbas region with a senior U.S. defense official telling reporters Friday that Russian morale "remains a problem" for Moscow. 

"We keep getting anecdotal indications…that morale and unit cohesion remains a problem," the defense official said. "Soldiers not obeying orders, or not fighting as well or as aggressively as they are being told to or expected to – even to the point where some officers are refusing to obey orders."

The official noted these reports depict a small narrative amongst the ranks and it is not believed to be an overwhelming factor prohibiting Russia’s progression in Ukraine. 

Russian soldiers are seen standing atop their military vehicles near the Zaporizhzhia Nuclear Power Station in southeastern Ukraine on Sunday, May 1.

Russian soldiers are seen standing atop their military vehicles near the Zaporizhzhia Nuclear Power Station in southeastern Ukraine on Sunday, May 1. (AP)

DEFENSE SECRETARY AUSTIN SPEAKS WITH RUSSIAN DEFENSE MINISTER FOR FIRST TIME IN MONTHS, URGES CEASEFIRE

But the official added, "It's consistent with the kinds of unit cohesion and morale problems we've seen in the past.

Despite nearly three months of intense fighting in their war-torn nation, Ukrainian troops are said to possess "a very strong will to fight there."

"Again, we don't have perfect visibility into every unit, but we're not seeing the kinds of unit cohesion and morale problems…in the Ukrainian armed forces," the official added. 

Russia continues to increase the number of battalion tactical groups deployed in Ukraine and 105 units are believed to currently be operational. 

Service members take part in a military parade on Victory Day, which marks the 77th anniversary of the victory over Nazi Germany in World War II, in the Chechen capital Grozny, Russia May 9, 2022. REUTERS/Chingis Kondarov

Service members take part in a military parade on Victory Day, which marks the 77th anniversary of the victory over Nazi Germany in World War II, in the Chechen capital Grozny, Russia May 9, 2022. (REUTERS/Chingis Kondarov)

UKRAINE DESTROYS 'SIGNIFICANT' NUMBER OF RUSSIAN ARMORED VEHICLES IN FAILED RIVER CROSSING, UK SAYS

The Pentagon continues to assess that Russia is at least two weeks behind where it would like to be and is only making "incremental gains" west of Popasna, a town located in the northeastern Luhansk region.

Ukrainians have seen successes in pushing Russian forces back toward the border in the north outside of Kharkiv. 

"The Russians not making any major gains in the Donbas," the senior defense official said, adding the war in Ukraine is "very much an artillery fight." 

Ukrainian soldiers examine Russian multiple missiles abandoned by Russian troops, in the village of Berezivka, Ukraine, on April 21.

Ukrainian soldiers examine Russian multiple missiles abandoned by Russian troops, in the village of Berezivka, Ukraine, on April 21. (AP/Efrem Lukatsky)

CLICK HERE TO GET THE FOX NEWS APP

"Ukrainian artillery is frustrating Russian efforts to make much ground and including frustrating their efforts to cross the Donets River as they continue to try to find a sense of momentum in the northern Donbas," the official added.  "The failure to make some of those crossings is affecting their ability to consolidate their forces…and that's affecting their ability to amass reinforcements."

Moscow still maintains the "vast majority" of it available combat force available to it though it is unclear how much territory is actually under Russian control in Ukraine, the senior defense official confirmed.