Ukraine says it now controls 100 Russian settlements and 1,294 square kilometres of Russian territory (500 square miles).
The incursion into the Kursk region began three weeks ago - last week, President Zelensky said Ukraine controlled more than 1,250 sq km of Russian territory.
Ukraine's commander in chief Oleksandr Syrskyi also says Ukraine has captured 594 Russian soldiers.
Earlier, Russia launched another wave of strikes on Ukraine, with four people killed, a day after one of its biggest air attacks of the war.
Zelensky says Kyiv will "undoubtedly respond to Russia for this and all other attacks".
