Russia occupies 20% of Ukraine's territory: Zelensky

"We have to defend ourselves against almost the entire Russian army. All combat-ready Russian military formations are involved in this aggression," Ukrainian President Volodymyr Zelensky said.

Russia is currently occupying about 20% of Ukraine's territory, Ukrainian President Volodymyr Zelensky told Luxembourg's parliament in a video address on Thursday.

Ukrainian President Volodymyr Zelensky.  (AP file photo)

"We have to defend ourselves against almost the entire Russian army. All combat-ready Russian military formations are involved in this aggression," he said, adding that the front lines of battle stretched across more than 1,000 kilometres (620 miles).