In Ukraine, the focus is the fighting, but are negotiations possible?

A wounded Ukrainian soldier who goes by the call sign Flame awaits evacuation after being injured in fighting near the eastern town of Bakhmut, Ukraine, on Sept. 4. Ukraine has been waging an offensive against Russian forces since June, but so far has made only limited gains. (Libkos/AP)

When Volodymyr Zelenskyy is asked if Ukraine should negotiate with Russian leader Vladimir Putin, the Ukrainian president is blunt.

"When you want to have compromises or have dialogue with somebody, you can't do it with a liar," Zelenskyy recently told CNN.