In a post on X, Zelensky refers to a report submitted by the Ukrainian Supreme Commander Oleksandr Syrskyj from Kursk and the front lines.
Zelensky also states that there is a risk of North Korea sending additional forces and equipment to the Russian military.
Ukraine's figures are higher than the estimates made in South Korea. There, it was recently concluded that around 1,100 men have been killed or injured in the Russian border region.
According to previous estimates, North Korea has so far sent approximately 11,000 soldiers to support Russia's war of aggression.
In the new South Korean assessment, it is also stated that North Korea's dictator Kim Jong-Un plans to send additional forces and deliver so-called suicide drones to the war.
Kim and Russian President Vladimir Putin have agreed to deepen military cooperation at top meetings in both Russia and North Korea.
Western analysts describe it as Putin turning to North Korea because Russia is in dire need of more soldiers for the war.
