Russian troops have surrendered en masse in the face of a rapid Ukrainian counter-attack that is continuing to gain ground, leading some to hope that a turning point in the war has finally been reached, media reports said.

Kiev's military intelligence said that many Russian soldiers had laid down their weapons rather than fight troops advancing east out of Kharkiv because "they understand the hopelessness of their situation", Daily Mail reported.

Oleksiy Arestovich, advisor to Ukrainian President Volodymyr Zelensky, said the military has captured so many Russian soldiers over the last several days that it is running out of space to house them - with military intelligence spokesman Andrey Yusov adding that "significant" number of Russian officers are among them, Daily Mail reported.

Meanwhile, Russian troops fighting a second counter-attack in the southern Kherson region were said to be negotiating their own surrender due to ammunition shortage -- though details from the frontline are sparse amid an information blackout imposed by Kiev.

In a late-night address, Zelensky said Ukraine's armies had captured a total of 2,300 square miles in the east and south since the beginning of September - an area about four times the size of Greater London - as he called on Western allies to supply more weapons to help consolidate the gains.

Ukraine and the West must "strengthen cooperation to defeat Russian terror", he said, while calling specifically for air defence systems to help protect civilian areas that Putin's commanders have begun targeting as 'revenge' for their battlefield defeats - blowing up power stations in the city of Kharkiv on Monday.

Zelensky described the strikes as "a sign of the desperation of those who invented this war". (KB/IANS)