The battle in Kursk is considered one of the most fierce clashes in the 3-year conflict between Russia and Ukraine. Last August, Ukrainian forces suddenly crossed the western border of Russia, launching the largest attack on Russian territory since the German socialist invasion in 1941.
However, a Russian counterattack this month has reduced the area under Ukrainian control to about 110 km2, down sharply from the more than 1,368 km2 that Kiev had declared control last year.
Map of the battlefields from both sides shows Ukrainian forces clustered into two small areas deep in Russian territory in Kursk.
Reuters reported that according to famous military blogger Yuri Podolyaka, Russia has pushed Ukrainian troops closer to the border in some areas, although fighting is still fierce and Ukraine has responded strongly when withdrawing. Russia said it was seeping a large number of mines in the area.
After US President Donald Trump called on Russia not to destroy the surrounded Ukrainian soldiers, Russian President Vladimir Putin said he was ready to ensure the lives of the Ukrainian soldiers if they surrendered.
Meanwhile, Ukrainian President Volodymyr Zelensky denied the reports that his army was surrounded but warned of a potential Russian attack on Sumy province, the area bordering Kursk in northeastern Ukraine.
The pro-Russian military blogger "The Two Major" said that Moscow's victories in Kursk are creating conditions for them to threaten Sumy, but stressed that Ukraine has reinforced the defense there for a long time.
President Putin accused Ukrainian soldiers of committing crimes against civilians in Kursk, something Kiev strongly denied.

The fierce war in Kursk is becoming the focus of diplomatic efforts to end the conflict. The US has just decided to resume military aid and share intelligence with Ukraine after Kiev announced its readiness to support Washington's proposal for a 30-day ceasefire.
President Putin said Russia supported the ceasefire "on principle" but stressed that the conflict could not be suspended unless important conditions were agreed.
Mr. Putin also affirmed his readiness for peace negotiations, but Ukraine must commit to giving up its ambition to join NATO and recognizing Russia's sovereignty over the territories that Moscow claims to control, including some areas that have not been completely controlled.
Both sides have paid the price for this conflict. According to US intelligence estimates in 2023, more than 100,000 Russian soldiers have been killed or injured, while the Russian economy is heavily affected by severe sanctions from the West.
On the Ukrainian side, more than 100,000 soldiers have also been killed, the economy has been devastated, and one-fifth of the territory is now under Russian control despite more than $260 billion in aid from the West.
However, neither Russia nor Ukraine have released official casualty figures.