Ukraine began a cross-border attack on Russian territory last week, claiming that the operation would make its position stronger when the time comes to negotiate a peace treaty with Moscow. Rodion Miroshnik, who leads a Russian Foreign Ministry special mission to investigate alleged Ukrainian war crimes, argued on Wednesday that the opposite is true.

“With their terrorist actions in Kursk, Ukraine at the very least put on a long pause the track of peace talks,” Miroshnik said during a media briefing. The diplomat described the move as a calculated step by Kiev.

Miroshnik was referring to attacks on civilians in border areas of Kursk Region. Russian President Vladimir Putin on Monday ruled out negotiations with Kiev, citing the same principle. He had previously said he was willing to order an immediate ceasefire in return for Ukrainian concessions on NATO membership and territorial claims.

“Holding negotiations with an opponent who is absolutely unhinged would be simply unnatural,” Miroshnik stated. Kiev targets civilians “to sow fear in society and spread discontent,” as part of a misguided “terrorist” military strategy, he claimed.

“The use of such methods only makes people clench their teeth and take every action to punish the perpetrator,” the diplomat stressed, adding, “This policy is implemented deliberately by [Ukrainian leader Volodymyr] Zelensky, and is a criminal phenomenon that goes against all principles of international humanitarian law.”

Zelensky has described the offensive as using “just force” to achieve “just peace” and a way to bring the war “home” to Russia. A key aide to the Ukrainian leader, Mikhail Podoliak, has said the goal of the incursion is to unsettle Russians so that they turn against their government.

“Today they have a war that is expanding deeper inside the Russian Federation. Will they fear that? Yes,” Podoliak claimed in an interview last week.

“Do they respond to anything but fear? No, and everyone should realize that at last.”

Western nations providing arms and other military assistance to Ukraine have endorsed Kiev’s actions on Russian soil, claiming they are legitimized by the right to self-defense.

Russian Foreign Ministry spokeswoman Maria Zakharova urged the UN on Wednesday to recognize as “terrorism” the actions of Ukrainian troops in Kursk Region.

Ukrainian President Volodymyr Zelensky said his forces are advancing in Russia’s southern Kursk region by 1 to 2 kilometers since the beginning of the day on Wednesday. Kyiv has already claimed to have control over some 1,000 square kilometers (386 square miles) of Russian territory since the start of its surprise assault.

“We are advancing in the Kursk region, 1 to 2 kilometers in various areas since the beginning of the day,” Zelensky said in a video call with Ukrainian military chief Oleksandr Syrskyi on Wednesday.

Zelensky also stated 100 Russian servicemen had been captured, adding that this will “accelerate the return of our guys and girls.”

The incursion – which poses a major embarrassment for the Kremlin – has prompted an angered Russia to take peace negotiations off the table for the foreseeable future.

The Russian Foreign Ministry’s special envoy, Rodion Miroshnik, said at a briefing on Wednesday that Moscow will be “at minimum” putting the talks with Ukraine on a “long pause”. Peace negotiations between the warring nations have proven unsuccessful since the start of the war in February 2022.

Meanwhile, the Russian border region of Belgorod declared an emergency on Wednesday after new attacks by Ukrainian forces.

“The situation in the Belgorod region continues to be extremely difficult and tense,” Belgorod Gov. Vyacheslav Gladkov said in a video message posted on his Telegram account on Wednesday.

The declaration came after Belgorod began evacuations on Monday as a result of Ukrainian advances.

It was a notable change in tactics for Ukraine and marked the first time foreign troops had entered Russian territory since World War II. Kyiv didn’t officially acknowledge its troops were operating inside Russia until several days later.

Regional authorities are now appealing to the Russian government to declare a federal emergency, Gladkov added.

Two locations in Belgorod, the city of Shebekino and the village of Ustinka, had been attacked by Ukrainian drones, he continued. There were no casualties but two residences were damaged.

Russia’s National Guard said on Wednesday that it had tightened security around the Kursk nuclear plant in Russia’s southwest following the surprise incursion. The National Guard, known as the ‘Rosgvardiya’, added that it had taken “additional measures” to protect the power plant.

Last week, the International Atomic Energy Agency said it was “monitoring the situation on the reported military activities taking place in the vicinity of the Kursk Nuclear Power Plant”, with its director general, Rafael Mariano Grossi, urging both sides to “exercise maximum restraint” in order to avoid “a nuclear accident”.

Since the incursion began, tens of thousands of Russians have fled their homes while Moscow scrambles to contain the attack, imposing counter-terror operations in Kursk, Belgorod and another border region, Bryansk.

On Monday, Kyiv claimed to have gained control of nearly the same amount of land that Russia had seized so far this year – though that is still dwarfed by the total Ukrainian territory held by Russia since the conflict started in 2014.

On Tuesday, Ukrainian President Volodymyr Zelensky claimed its forces were in control of 74 settlements in Kursk and that they are making preparations for “next steps” in the region.

Russian President Vladimir Putin has meanwhile vowed to “kick the enemy out” of Russia – though his troops have yet to stop the Ukrainian advance.

US President Joe Biden addressed the incursion on Tuesday, saying he was receiving regular updates from staff and that it was “creating a real dilemma for Putin”.