Ukraine seizes broad swath of Russian territory in cross-border assault

• Putin dubbed the Ukrainian incursion a "major provocation" and vowed Monday that Russia would deliver a "worthy response" to the offensive, Reuters reported.

Driving the news: Gen. Oleksandr Syrskyi confirmed in a Telegram post Monday that Ukraine has seized roughly 1,000 square kilometers (386 square miles) of Russian territory.

• The announcement comes after battles have raged in Russia's Kursk border region since Ukraine's incursion began last Tuesday.
• "Russia brought war to others, and now it is coming home," Zelensky said in a Telegram post Monday.

Zoom in: A new assessment issued Monday by the Institute for the Study of War estimated that Ukraine had seized roughly 800 square miles of Russian territory.

• Axios could not independently verify how much territory Ukraine had seized.
• The Institute also noted that Ukrainian forces are continuing their advance into Kursk, refuting claims by Russian military bloggers who have said that "Russian forces were stabilizing the frontline" in Kursk.

The other side: The Russian Defense Ministry said Tuesday that Russian forces had repelled further breakthroughs by Ukrainian forces in the Kursk region, Russian state news agency TASS reported.

• Alexei Smirnov, the acting governor of the Kursk region, told Putin on Monday that more than 120,000 people have already been evacuated from the region, Russian media reported.

Zoom out: Ukraine's assault comes several months after Russia had launched a new offensive on Ukraine's northeast Kharkiv region.

Go deeper: Russia launches new assault on Ukraine's northern Kharkiv region