The Russians are preparing for a new offensive in eastern Ukraine, a US official has warned

Though Russian forces still remain north of Izyum, the official said, the United States estimates the vehicle line includes a command and control element and a support group battalion, as well as possible rotorcraft aviation support and other infantry support.

“We believe this is an early attempt by the Russians to strengthen their presence and capabilities in Donbass,” the official said, adding that the developments “are clear evidence of what we’ve been saying for some time: that the Russians will want to pump more of their wealth into the Donbass.”

Russia’s planned attack on the Donbass comes after its forces retreated from around the capital Kyiv in recent days after encountering stiff Ukrainian resistance. Their hasty retreat exposed scenes of apparent war crimes and other atrocities in Bucha and other Kyiv suburbs.

Now, the official said on Monday, “The location of everything we’re seeing is the Donbass region,” from which Russia launched its latest invasion of Ukraine in February, 47 days ago.

Before proceeding with a full-scale invasion of the country, Russia first moved troops across its western border into the Donbass, home to two breakaway territories largely held by Moscow-backed separatists: the so-called Donetsk People’s Republic and the Luhansk People’s Republic.

The United States “does not yet assess that a new offensive has begun in Donbas,” the official said Monday. However, the official noted that a “hot war” has been raging in the region since 2014 – when fighting began between Ukrainians and Moscow-backed pro-Russian separatists.

The official also said the United States believes Russia has indeed appointed General Alexander Dvornikov to lead its war effort in Ukraine, reports reported over the weekend.

Dvornikov previously oversaw Russian forces in Syria, and his brutal tactics there have sparked fears in the United States that the invasion of Ukraine could become even more violent as the fighting shifts east.

But the official said on Monday that “it remains to be seen what effect” Dvornikov will have on Russian forces, which are facing significant logistical and morale problems amid the protracted conflict.

“They face great challenges, and being elected a general doesn’t mean they’re primed for greater accomplishments here,” the official said. “We’ll just have to wait and see.”