Ukraine has launched a counterattack in in the southern Russian border region of Kursk, with the presidency saying Russia is “getting what it deserves.”

The Ukrainian military first launched an incursion into Kursk in August and has held much of the territory it took, despite efforts by Russian and recently deployed North Korean troops to drive Ukrainian units back across the border.

In a short Telegram post Sunday, the head of the Ukrainian Presidential Office, Andriy Yermak, said: “Kursk region, good news, Russia is getting what it deserves.”

Andrii Kovalenko, the head of the Ukrainian Center for Countering Disinformation, an official body, said Ukrainian forces had launched surprise attacks against Russian forces in several locations.

The Russian Defense Ministry said Sunday that the Ukrainians had launched counterattacks to stop a Russian offensive, according to the official TASS news agency. It said that both had been repelled, adding that a Ukrainian assault including two tanks and seven armored vehicles had been defeated near the village of Berdin, some 15 kilometers (9 miles) from the border.

CNN is unable to verify battlefield reports.

On Saturday, Ukraine’s President Volodymyr Zelensky said that in battles near the village of Makhnovka, the Russian army lost up to a battalion of North Korean soldiers and Russian paratroopers. A battalion is normally several hundred troops.

Unofficial Russian military blogs, which often provide reliable reporting on the Ukraine conflict, acknowledged the fighting on Sunday. One said that the Ukrainians were pushing north towards Berdin.

“The enemy has thrown reserves into the offensive in Kursk region,” said one blog Sunday.

“For the breakthrough, the AFU covered the area with powerful radio electronic warfare systems, hampering the work of our UAVs [drones],” the blog said. “There are small arms battles, our artillery and tanks are actively working against the enemy.”

A second blog carried a similar account, saying the offensive had begun from the Sudzha area, but the Ukrainians had also landed paratroopers and intensified fighting in other directions.

“In this offensive the enemy uses mine clearance trawls, tanks and other armored vehicles,” the blog said, adding that frosty ground was enabling the attack, but that was not expected to last. It added that Russian bombers were in action.

The acting governor of Kursk, Aleksandr Hinshtein, said on Telegram that the Russian Deputy Minister of Defense, Yunus-Bek Yevkurov, had arrived in the region. Yevkurov is responsible for military security in the border regions, but it’s not clear that his visit is linked to the current fighting.

“The government of the Kursk region will do everything possible to help our Armed Forces in their holy struggle against Nazism,” Hinshtein said.

Ukrainian and western assessments say that some 11,000 North Korean troops are deployed in the Kursk region, where Ukrainian forces occupy swathes of territory after staging the cross-border incursion.

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