Fighting in Russia has been ongoing for a third day after a Ukrainian force of 1,000 troops crossed the border into the Kursk region on Tuesday, marking one of the most significant incursions since the war began over two years ago.

Moscow declared a state of emergency in the Kursk region, located about 175 miles northeast of the Ukrainian city of Kharkiv, following reports that Ukrainian forces had breached at least two lines of defense, according to open-source reporting outlined by the Institute for the Study of War.

Footage released by the Ukrainian defense ministry on Thursday showed dozens of Russian soldiers surrendering to Ukrainian troops. Reports from pro-Russian bloggers suggest that Ukraine is continuing to advance northward in the Kursk region.

The specific operational goals of Ukraine remain unclear, with Kyiv maintaining a policy of silence on the matter.

However, Mykhailo Podolyak, a top advisor to Ukrainian President Volodymyr Zelenskyy, offered some insight into the motivation behind the incursion in his first statement since the cross-border invasion into Russia.

“The root cause of any escalation, shelling, military actions, forced evacuations, and destruction of normal life forms, including within [the Russian Federation’s] own territories like Kursk and Belgorod regions, is solely Russia’s unequivocal aggression,” he said on X. “Russia has consistently believed that restrictive legal norms do not apply to it.

“But war is war, with its own rules, where the aggressor inevitably reaps corresponding outcomes,” he added.

Open-source reporting from Russian bloggers indicates that despite purportedly suffering heavy losses, Ukrainian forces successfully captured a key military checkpoint and the Sudzha gas distribution station, which ensures the continuous trans-shipment of natural gas from Russia to Europe. They continue to expand their offensive across the region.

Images and reports have confirmed the evacuation of Russian civilians from the Kursk region. While precise figures on the number of evacuees remain unclear, reports suggest that between 3,000 and 10,000 civilians have fled the fighting.

Russian President Vladimir Putin reportedly characterized the assault as a “major provocation” after a meeting with top security officials on Wednesday, although Moscow has not confirmed the seizure of the Sudzha distribution station.

Army Gen. Valery Gerasimov, Russia’s chief of the general staff, reportedly informed Putin and other senior officials during the meeting that Russian forces had halted Ukraine’s advances.

However, on-the-ground information contradicts the Kremlin’s statements. Pro-Russian military blogger Yuri Podolyaka said, “Sudzha is basically lost to us. And this is an important logistics hub,” . “In general, the situation is difficult and continues to deteriorate, despite the fact that the pace of the Ukrainian offensive has noticeably dropped.”

Pro-Russian bloggers have also stated that Ukrainian forces continue to press northward toward the Russian town of Lgov, a settlement just 20 miles from the Kursk Nuclear Power Plant.

Some reports have suggested that Ukraine may have its sights set on the power plant, although it remains unclear how Kyiv would intend to secure the plant or the territory it could potentially gain.

The extent of losses sustained by Ukrainian forces in Russia is unknown.

Zelenskyy did not mention the operation in Russia during his nightly address to the nation on Wednesday. Instead, he said he had spoken to his Commander-in-Chief Oleksandr Syrskyi and that “details would follow later.”

When pressed for details regarding Ukraine’s operation in Russia, White House National Security Council communications adviser John Kirby stated that he would defer to Kyiv on matters concerning its military operations.

However, he added, “Nothing has changed about our policy with respect to enabling or encouraging strikes or attacks inside Russia.”

The Biden administration has relaxed some of its opposition to Ukraine striking strategic targets inside Russia using U.S.-supplied weaponry, provided that they “target imminent threats just across the border.”