KHARKIV, Ukraine -- The situation in Ukraine is so serious that President Volodymyr Zelenskyy had to cancel a planned trip to Spain and come straight to Kharkiv -- the country's second largest city, which is again in real danger from the Russian advance.

With exclusive access, ABC News joined Zelenskyy on a tour of a hospital in the city, with Zelenskyy, where he met soldiers injured in the northern defense, and presented them with medals of valor.

"It's really important for me to be here," he told us, as we walked the corridors.