Ukraine has captured more Russian land in a week than the Kremlin’s forces have managed in more than eight months of cross-border warfare.

On Monday, Kyiv’s top general claimed that his forces were in control of 1,000 sq km (386 sq miles) of Kursk, a border region in southern Russia.

The Telegraph has not been able to verify the figure. Independent analysts have suggested lower totals for the size of Ukraine’s advance.

But Russian officials have admitted that Kyiv controls 28 settlements after opening an area more than seven miles over the border and almost 25 miles wide.

The operation has drawn Moscow’s attention away from eastern Ukraine, where Russia has been slowly advancing for months.

Before Kyiv’s cross-border attack, the Russian army had reached within a short distance of Pokrovsk, a key garrison city in the Donetsk region, and was close to capturing the towns Chasiv Yar, Toretsk and Niu-York.

However, a Telegraph analysis of Russian gains found that it has taken more than eight months to capture 994 sq km of territory.

Moscow has not been able to capture a 1,000 sq km swath of land in any month from Dec 1, 2023 to the present day.

During that time, Moscow has lost around 300,000 troops, killed or wounded, according to estimates published by the Ukrainian military.

It has fought through heavily fortified Ukrainian positions, using slow-moving infantry advances and destructive artillery barrages.

Those grinding advances sped up with the February 2024 capture of Avdiivka, an industrial city in Donetsk. That paved the way for the capture of more territory, as Ukrainian forces suffered from ammunition shortages amid a stalled US aid package.

Despite supplies starting to reach Kyiv’s front-line positions, its outgunned and outnumbered troops have been unable to put a stop to the Russian offensive.

Russia’s most successful month on the battlefield came in May 2024 when its forces opened up a new front, launching a cross-border invasion into Ukraine’s north-eastern Kharkiv region.

However, Moscow only managed to capture around 250 sq km which at the time was its biggest gain in 17 months.

Putin’s troops were able to advance six miles into the region before Kyiv managed to stabilise the situation.

The Kursk operation has boosted morale in the Ukrainian army after months of battlefield losses.

It is not clear how long Ukraine will seek to hold onto its newly seized land over the border in Russia, which could become a bargaining chip in any future peace talks.

Russia has begun rushing reinforcements into the region, with Putin vowing to drive his Ukrainian enemy from Russian soil.

On Tuesday Apti Alaudino, who commands the Chechen Akhmat special forces unit, said Russia had started to retake some of its territory.