The UK intel said that the Russian army was supposed to be tough enough to fight NATO.

Britain's Ministry of Defence said in a Tuesday intelligence update that the 1st Guards Tank Army was among the Russian forces who fled the Kharkiv region in easternUkraine.

The troops had to retreat after the Ukrainians retook swaths of territory from the Russians.

The British update said that 1GTA was not fully equipped to deal with the offensive because it had suffered a lot of casualties in the first few months.

One of the most prestigious of Russia's armies is the 1GTA, which is charged with defending Moscow and leading counter- attacks in the event of a war with NATO.

Russia's force designed to counter NATO is severely weakened by the loss of 1 GTA. Russia will likely take a long time to rebuild this capability.

The retreat in Kharkiv is the most recent blow to Russian military prestige.

The Russian air force, as well as the elite paratroopers known as the VDV, failed to overwhelm the less advanced counterpart of the Ukrainian army.

Russia'sMinistry of Defense confirmed that its forces retreated from some areas in the Kharkiv region, with a top official saying on Russian TV that Ukrainian forces outnumbered Russians by eight to one.

Russian soldiers were forced to flee in a variety of ways, including disguising themselves as locals, due to the fast attack.

Ukrainian President Volodymyr Zelenskyy said in his address on Monday that his country had regained around 2,300 square miles since the beginning of September.

The Institute for the Study of War concluded that the counteroffensive by Russia was a major operational defeat.