A senior Ukrainian official says Russia has started its major offensive in Ukraine. But he has stressed that his nation's forces are "powerfully repelling it."

Ukraine's National Security and Defense Council Secretary Oleksiy Danilov spoke to a local media outlet on Saturday.

Danilov said the offensive Russia planned is gradually underway. But he said it is not the offensive Russia was counting on.

Ukraine stays vigilant for large Russian offensives in the run-up to the first anniversary of the invasion on February 24.

Russian forces are continuing their push to capture the Ukrainian stronghold of Bakhmut in the eastern region of Donetsk.

The head of Russian private military company Wagner Group said in a social media post on Sunday that the mercenary force took a settlement on the edge of Bakhmut.

Meanwhile, Ukraine's defense minister Oleksii Reznikov tweeted on Saturday that he held phone talks with US Defense Secretary Lloyd Austin.

Reznikov said they discussed the latest frontline situation and "priorities" for an upcoming conference of Western nations on military aid for Ukraine.

The Ukrainian military's Commander-in-Chief Valerii Zaluzhnyi also tweeted on Saturday that he held a phone conversation with US Joint Chiefs of Staff Chairman General Mark Milley.

Zaluzhnyi said the tensest situation now is "along the Donetsk axis." But he said Ukraine continues to hold Bakhmut under its control despite constant enemy pressure.

Zaluzhnyi added, "The key to success on the battlefield is effective fire, which requires an appropriate amount of weapons, equipment, and ammunition."