inside the country with a very specific mission, assassinate ukrainian president volodymyr zelenskyy. cnn's david mckenzie has the story. >> reporter: a russian mercenary takes a selfie video in syria. it's a recruitment-style pitch allegedly for the notorious wagner group, a brutal force believe linked to the kremlin. in the shadows of russia's invasion of ukraine, a senior ukrainian defense official tells us that wagner contractors were in the country and had a very specific mission. what is the objective, do you think, in ukraine right now? >> they wanted to assassinate the leadership of ukraine, of the president and prime minister. so that was the goal, and a couple of groups -- i couple of people were sent to ukraine without any success. >> translator: i am here. we are not putting down arms.