Zelensky confirms Ukrainian troops are fighting inside Russian territory

Ukrainian President Volodymyr Zelensky has confirmed Kyiv’s troops are fighting inside Russia, days into the surprise Ukrainian cross-border incursion into Russia’s Kursk region that has become a major embarrassment for the Kremlin.

“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,” Zelensky said in his nightly address to the nation on Saturday, thanking “every unit” of Ukraine’s armed forces for making it possible “to push the war out into the aggressor’s territory.”

The statement marked the first time Zelensky officially acknowledged the incursion, which took by surprise both Russia and Ukraine’s allies. Ukrainian officials have for days remained tight-lipped about the operation, even as photographs, videos and firsthand reports of Ukrainian soldiers inside Russia started to emerge.

Moscow has been scrambling to contain the attack. Russian authorities imposed a sweeping counter-terror operation in Kursk and two other border regions and tens of thousands of people have been evacuated from Kursk.

Now into its sixth day, the attack on Kursk is a significant development in the more than two-year old conflict.

Ukraine has repeatedly targeted the border region of Belgorod with airstrikes and pro-Ukrainian sabotage groups have conducted limited cross-border attacks, but the Kursk operation marked the first time that regular Ukrainian and special operations units have entered Russian territory.

The surprise factor appear to have worked: as of Sunday, Russian troops seemed to struggle to stop the Ukrainian advances and push Kyiv troops back.

In his next address on Sunday, Zelensky said that thousands of strikes on Ukraine’s territory launched from Russia’s Kursk region deserve a fair response.

“Since the beginning of this summer alone, almost 2,000 strikes have been made on our Sumy region from districts of the Kursk region only: artillery, mortars, drones. We also document every missile strike,” he said adding that “every one of these strikes deserves a fair response.”

Recent Ukrainian missile and drone strikes on Russia show that Kyiv has been living up to Zelensky’s words.

Russia said Sunday it foiled a Ukrainian attack that launched drones and Tochka-U tactical missiles. Its Ministry of Defense said it destroyed 14 drones and 4 Tochka-U tactical missiles over the Kursk region, 16 drones over the Voronezh region, three drones over the Belgorod region, and one drone each over the Bryansk and Oryol regions.

The Institute for the Study of War (ISW), a US-based conflict monitoring group, said in its latest assesment on Sunday that geolocated footage and Russian reporting from Saturday indicated that Ukrainian forces maintained their positions in the region and have advanced slightly further.

By Friday Russian authorities had lost control over at least 250 square kilometers of territory, according to several independent analyses and CNN’s mapping.

Videos posted on social media appear to show Ukrainian troops taking down Russian flags in Russia’s Kursk region and replacing them with Ukrainian flags.

The governor of Kursk region has urged authorities there to speed up evacuations on Sunday. More than 76,000 people from the border areas had left their homes as as of Saturday, according to the Russian state news agency TASS .

Russian authorities imposed a “counterterrorist operation regime” in Kursk, Bryansk and Belgorod regions on Friday, stopping short of declaring state of war or martial law.

ISW said this was was likely an attempt by the Kremlin to deliberately downplay the assault to prevent domestic panic or backlash over the fact that Russia was unable to defend its own borders.

“Russian President Vladimir Putin has refrained from officially declaring a state of war, has repeatedly demonstrated his unwillingness to transfer Russian society fully to a war-time footing, and has forgone declaring general mobilization as part of wider efforts to prevent domestic discontent that could threaten the stability of (his) regime,” the ISW said in its update.

The counterterrorist regime officially gives Russian authorities wider powers, including the ability to monitor telephone conversations and restrict communications and limiting the movement of people.

The surprise attack in Kursk, which Putin called a “major provocation,” has been a significant win for Kyiv as it continues to struggle to hang onto its territory along parts of the 1,000 kilometre frontline.

Moscow has pushed on with its slow, grinding offensive, edging closer in recent weeks to several strategically important towns and roads in eastern Ukraine.

Early on Sunday, Moscow launched drone and missile attacks against Kyiv region, according to local officials. A four-year-old boy and his father were killed in a Russian strike in Brovary, just east of the capital city, the officials said, adding that another child was seriously injured.

The attack came after a strike on a supermarket in the Ukrainian town of Kostiantynivka in Donetsk region left at least 11 people dead and 37 injured, according to authorities.

In a video statement released on Sunday, Zelensky said that “this week alone, the Russian army launched more than 30 missiles and over 800 guided aerial bombs,”

Mykola Oleshchuk, Ukrainian Air Force Commander, said Russia attacked Ukraine using, among other weapons, North Korean KN-23 ballistic missiles and Iran-made Shahed drones. CNN cannot independently verify that claim.

It has been a deadly summer for Ukrainian people, with July marking the deadliest month for civilian casualties since October 2022, according to UN human rights monitors.

The UN Human Rights Monitoring Mission in Ukraine (HRMMU) said at least 219 civilians were were killed and 1,018 injured in what the agency previously called a “deadly wave of missile strikes on densely populated areas of Ukraine.”

This story has been updated with additional developments Sunday.

CNN’s Eve Brennan, Isaac Yee, Radina Gigova and Olga Voytovich contributed reporting.