Ukraine does not see a threat to Kharkiv itself from the Russian attack, but the Russians have concentrated about 50,000 invaders on the border – with "more than 30,000" taking part in the attack, Secretary of the National Security and Defense Council (NSDC) Oleksandr Lytvynenko said in an interview with AFP.

"At the moment, Russian actions in the border area are ongoing. We can say that we don't see any threat of assault on the city of Kharkiv. But there are a lot of Russians, quite a lot. About 50,000 were on the border," he said.

Lytvynenko stated that "more than 30,000" occupiers are taking part in the current attack.

The official noted that any new Russian attack on Kharkiv would cause devastation, the displacement of more than a million people, and inflict "enormous damage" on Ukraine's economy.

In his opinion, Russia's current offensive is likely aimed at creating a "buffer zone" along the border to limit Ukrainian attacks on Russia, which have intensified in recent months.

The secretary of the NSDC said that Ukraine had struck inside Russian territory, but stressed that this was only against military and oil and gas facilities used by the invaders for the invasion.

He noted that Russia has lost about 15% of its oil refining capacity: "It is very important that Ukraine is hitting legitimate targets."

Russia began its offensive on Kharkiv Oblast when Ukraine was running out of weapons, even though it had begun to receive aid from the United States, Lytvynenko said.

"They [the Russians] are taking advantage of their current advantages, advantages in reserves, advantages in weapons, and are trying to force our army to retreat," he said.

If the US aid had arrived earlier, "it would have been better. But the fact that it is already coming is a huge advantage," the secretary noted.

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