Ukrainian President Volodymyr Zelensky said Monday that Russia has deployed nearly 50,000 troops to Kursk, the southern Russian region where Kyiv launched its surprise counteroffensive in the summer.

Experts tell Andy Gregory and Tom Watling that the real question is how much Kyiv’s troops are able to inflict casualties on the Russians as the price for taking the territory back

Ukraine's president says the incursion is limiting the forces Moscow can deploy inside his country.