By Idrees Ali and Phil Stewart
WASHINGTON -The United States assesses that Russia is prioritizing eastern Ukraine's Donbass, as opposed to Kyiv, in what could be an effort to build leverage in negotiations and cut off Ukrainian forces in the east from the rest of the country, a senior U.S. defense official said on Friday.
Russia said earlier on Friday that the first phase of its military operation was mostly complete and it would focus on completely "liberating" Ukraine's breakaway eastern Donbass region.
The announcement appeared to indicate Moscow may be switching to more limited objectives after running into fierce Ukrainian resistance in a month of war.
The senior U.S. official suggested Russia's activities on the ground appeared broadly to back up Moscow's announcement.
"They are prioritizing it and we concur, our information would concur, with that," the official, speaking on condition of anonymity, told reporters.
The official said the United States was seeing Russian forces become more aggressive in the Donbass area.
"They have certainly made it a higher priority on their list," the official added.
The city of Kherson, a regional capital of about 250,000 people, did not seem to be as solidly in Russian control as it was before and appeared to be contested, the official said.
Kherson was the first big urban center to fall into the hands of Russian troops after they invaded Ukraine on Feb. 24.
Russian troops have largely stalled around Kyiv and are establishing defensive positions, the official said.
On Friday, Sergei Rudskoi, head of the Russian General Staff's Main Operational Directorate, said 1,351 Russian soldiers had died in the operation and 3,825 been injured. Ukraine's military has said some 15,000 Russian soldiers have been killed in combat.
Russia's combat power in Ukraine was somewhere between 85 and less than 90% of its pre-invasion levels, the U.S. defense official said.
For the first time, the official said, the United States had signs that Russia was looking to draw on its troops in Georgia to help in Ukraine.
It was unclear what their timeline was and where exactly they would go, but the official said it would not be surprising if they were sent into the Donbass region.
Ukrainian authorities have said Russian forces had effectively surrounded the northern city of Chernihiv and were bombarding areas where residents were stuck without electricity, heating and water.
The U.S. official said Ukrainian forces were making incremental progress against Russian troops around Chernihiv.
On Thursday, Ukraine said it had destroyed a large Russian landing support ship at the Russian-occupied port of Berdiansk on the Sea of Azov.
The U.S. official confirmed Ukrainian forces had destroyed the Russian warship in Berdiansk, but it was unclear how many casualties there had been.