A report by The Washington Post (WP) said, "As President Volodymyr Zelensky traveled through Europe and the United States to promote his “victory plan” aimed at resolving the war with Russia, Ukrainian forces encountered significant setbacks on the battlefield"

Analysts indicated that Russian forces may have been driven back in up to half of the territory that Kiev originally captured during its summer offensive into Russia’s Kursk region. According to WP, this concerning shift calls into question the effectiveness of Ukraine’s military strategy amid the ongoing conflict.
 
The incursion into Russia was initially celebrated by Ukrainian officials as a success, however, recent Russian counterattacks in the Kursk region have raised concerns about how long Kiev can maintain control over the territory.

The Institute for the Study of War, which has been closely monitoring the conflict, reported visual evidence indicating that Russian forces have regained control of 46% of the territories in the Kursk region.

Russian President Vladimir Putin said that pockets of Ukrainian forces in the region had been encircled, however, this assertion was strongly disputed on Friday by Oleksandr Syrsky, the commander of Ukraine’s armed forces, according to WP. 

He posted on Telegram, “Ukrainian forces continue active operations in the Kursk direction, for the third consecutive month, destroying the enemy’s combat potential,” adding that “Despite the immense pressure from the enemy on this front, the occupiers are suffering significant losses in personnel and military equipment.”

The Washington Post stated that Ukraine’s recent losses in Kursk highlight the country’s ongoing military struggles even as talks to end the war continue, adding that Russia has steadily gained ground in Ukraine’s eastern Donetsk region and has recently made further advances in the northeastern Kharkiv region, aiming to reach the city of Kupyansk.
 
Kiev's territorial gains in the Kursk region were featured in Zelensky's victory plan, with Ukrainian officials portraying the incursion as a potentially significant leverage point in future peace negotiations, however, Russia’s recent advances are reframing the perspective, according to the report. 

“I don’t think we can talk about the large-scale Russian offensive that could push the Ukrainians out just yet,” said Franz-Stefan Gady, a Vienna-based military analyst. “I think we’re still in a shaping phase — that is, in a preliminary phase before a larger-scale assault — and the major objective of the Russian forces currently is to [weaken] Ukrainian forces with artillery and drone strikes.”

“They’re essentially just testing the weaknesses of the Ukrainian defenses, so the incursion’s still fairly limited. And I think what’s concerning is that the Ukrainians are indeed actually already in this phase of being pushed back,” he added.