U.S. national-security adviser Jake Sullivan says Russian forces are repositioning to regions of Ukraine in the east and south after meeting stronger Ukrainian resistance than they expected near Kyiv.
"At this juncture we believe Russia is revising its war aims" to focus on "eastern and parts of southern Ukraine rather than target most of the territory," Sullivan said at a briefing on April 4.
The goal is likely to "surround and overwhelm" Ukrainian forces in the region, he said.
"Russia could then use any tactical success it achieves to propagate a narrative of progress and mask...prior military failure."
Sullivan warned that Russia was redoubling its efforts after pulling many troops from around the capital and will fight to take significantly more territory than the Moscow-backed separatists held in the region, commonly known as the Donbas, prior to the launch of Russia's invasion on February 24.
The United States also expects Russian military forces to do what they can to hold the city of Kherson in the south and Kharkiv in the east, Sullivan told reporters at the White House on April 4.
But Sullivan described the pullback of Russian forces from areas around Kyiv as a retreat, saying they did not achieve their objectives and stressed that that United States will continue to support Ukraine with military and humanitarian aid.
"The Russians have now realized that the West will not break" in its support of the Ukrainian government, Sullivan said.
Sullivan said Washington will have announcements of additional military assistance for Ukraine in the coming days, adding that the next phase of the war in Ukraine could last "months or longer."
In response to the killings of civilians in the town of Bucha, he said the United States was coordinating with its allies in Europe and plans to announce new sanctions against Russia this week.
SEE ALSO: 'Russia Must Answer To The World': Global Condemnation Of Ukraine Killings MountsAsked whether the White House agreed with assessments by Ukrainian President Volodymyr Zelenskiy that genocide was committed in Bucha, Sullivan said: "We have seen atrocities, we have seen war crimes, we have not yet seen a level of systematic deprivation of life of the Ukrainian people to rise to the level of genocide."
He said the International Criminal Court could be the venue for a war crimes trial, and the United States will consult its allies about holding Russia accountable for the killings of civilians in Bucha.