Putin's response comes after Ukrainian President Volodymyr Zelenskyy confirmed that Kyiv's troops have crossed the border into Russia and are fighting in the Kursk region.

"Ukraine is proving that it really knows how to restore justice and guarantees exactly the kind of pressure that is needed – pressure on the aggressor,” stated Zelenskyy as he confirmed Ukrainian presence in Russia.

Last week, Ukrainian forces crossed the border into Russia's Kursk Region, marking the biggest across-the-border action since the start of the war in 2022. As per Ukraine's army chief Oleksandr Syrskyii, Kyiv now controls about 1,000sq km (386sq miles) of Kursk.

In the past six days of Ukrainian attacks in Kursk region, governor Alexei Smirnov has stated that around 28 settlements have been lost, 12 civilians killed and around 121,000 people have been evacuated from the region.

Ukraine's incursion reportedly caught Russia by surprise but Moscow has hit back and deployed its own troops in Kursk to push back Ukrainian forces.

“Heavy tracked vehicles are being loaded onto automobile trailers for prompt delivery to the areas where Ukrainian Armed Forces formations are being blocked and to ensure the safety of the road surface,” stated the Russian military.

Tensions Escalate As Russia-Ukraine War Enters Day 900

The tensions between Russia and Ukraine have escalated dramatically in the past few months. On Sunday, Ukraine accused Russia of setting a fire in one of the cooling towers of the Zaporizhzhia nuclear plant. Moscow has denied this accusation and blamed Ukrainian troops for the damage.

Russia captured the Zaporizhzhia nuclear plant a few weeks into the invasion. Since then, the Ukrainian government and the International Atomic Energy Agency have urged for nuclear calm and return the control of the nuclear facility to Ukraine.

Following Ukraine's Kursk incursion, China has also stepped in and called for urgent de-escalation. “China will continue to maintain communication with the international community and play a constructive role in promoting a political solution to the crisis,” stated the spokesperson from the Chinese Foreign Affairs ministry.

Additionally, Switzerland and Italy have called for Russia's participation in the next round of the Ukraine peace talks in November. Moscow had not been invited to the first round of peace talks in Switzerland, which was condemned by many allies.

However, Zelenskyy stated later on that an invite will be sent to Russia for the second round.