Russia claimed a significant advance in eastern Ukraine on Monday, while pro-Moscow war bloggers reported ongoing efforts to repel a Ukrainian offensive within Russian territory.
The Russian Defense Ministry said its forces had captured the town of Kurakhove, 32 kilometers (20 miles) south of Pokrovsk, a Ukrainian logistics hub toward which Russian forces have been advancing for months.
The ministry said taking Kurakhove, which had held out for many weeks, would enable Moscow's forces to step up the pace of their advance in Ukraine's Donetsk region.
Ukrainian monitoring group DeepState, which tracks the front line using open sources, showed most of Kurakhove under Russian control.
Ukraine's Khortytsia group of forces said Russian forces continued to attack Kurakhove but the Ukrainian side was working to identify and repel Russian assault groups on that part of the front.
Russian war bloggers said Ukraine was attacking the Kursk region for a second day. One of them described the situation as concerning.
Ukraine began a new offensive Sunday in Kursk, where its forces broke across the border on Aug. 6 and for the past five months have resisted Russian attempts to expel them.
Russia's Defense Ministry said its forces beat back the first Ukrainian attacks Sunday just north of a highway running toward the regional capital Kursk.
But Russian military bloggers – a group of war correspondents and experts who, while supporting Moscow's effort, have often criticized its shortcomings – said fierce fighting was continuing for a second day.
"The morning in the Kursk region is starting off worryingly again. It is obvious that yesterday's failure will not stop the enemy and he will try to impose his will on us again today," one blogger, Yuri Podolyaka, posted on Telegram.
Russia controls about a fifth of Ukraine after nearly three years of war but Ukraine's success in seizing and retaining a slice of Russian territory could boost its negotiating position as both sides prepare for possible peace talks this year.
Both have been striving to improve their battlefield positions before U.S. President-elect Donald Trump is sworn in on Jan. 20. Trump has repeatedly said he will bring a quick end to the war, without saying how.
Ukrainian and Western assessments suggest about 11,000 troops from Russian ally North Korea have been deployed in the Kursk region to support Moscow's forces. Russia has neither confirmed nor denied their presence.
U.S. Secretary of State Antony Blinken said Monday more than 1,000 North Korean troops had been killed or wounded. Reuters does not have access to the Kursk war zone and cannot verify battlefield accounts or casualty counts.
Reacting to the new Ukrainian offensive, the United States and Britain reaffirmed support for Kyiv on Sunday.
"We are committed to putting Ukraine in the strongest possible position on the battlefield, including by surging security assistance and utilizing all available resources authorized by the Congress," a U.S. State Department spokesperson said.
A spokesperson for Britain's Foreign, Commonwealth and Development Office said: "Ukraine has a right of self-defense against Russia’s illegal, unprovoked and barbaric invasion. The U.K. will support Ukraine for as long as it takes."