Russian forces are attempting to create an active fighting zone in Ukraine's northeastern region of Sumy, across the border from Russia's Kursk region, Ukraine's border guard spokesman said on Monday.

Russia has launched a cross-border offensive in Ukraine's Sumy region, Ukraine's border guard said on Monday, and in recent days has stopped up its pressure on Ukrainian troops holding parts of its

"These are small assault units, composed of a few people. They try to penetrate our territory, accumulate forces and advance further into Ukraine, probably to cut off logistical routes," State Border Guard spokesperson Andrii Demchenko said on national television.

A Russian offensive supported by North Korean troops in the past few days has made a serious advance in Russia's Kursk region northeast of Ukraine, breaking through Ukrainian positions and forcing them to withdraw to new defense lines,

The officials said clashes were taking place in the Novenke area. Sumy is located across the border from Russia’s Kursk region, where Ukrainian troops launched an offensive in August. Russian forces occupied parts of Sumy during the early part of their full-scale invasion of Ukraine that began more than three years ago.

Russia on Sunday announced it had captured territory in Ukraine's Sumy region for the first time since 2022 in a cross-border offensive, as Kyiv struggles to hold onto territory in

Ukraine is sending reinforcements to support its forces in Russia's Kursk region, the Ukrainian army's top commander said Monday, coming as the Russian military claims to be speeding up the advance of its counteroffensive in the border region.