KYIV, Ukraine -- Ukrainian President Volodymyr Zelesnkyy spoke defiantly Friday in two speeches about his country's ultimate victory over Russian forces in both the most pressing battle in eastern Ukraine and the war, generally.

"Ukraine is a country that has destroyed the myth about the extraordinary power of the Russian army -- an army that supposedly, in a few days, could conquer anyone it wants," he told Stanford University students by video. "Now Russia is trying to occupy the entire state but we feel strong enough to think about the future of Ukraine, which will be open to the world."

Later, in his nightly video address, Zelenskyy reacted to Russians' capture of the eastern city of Lyman, the Donetsk region's large railway hub north of two more key cities still under Ukrainian control, and its attempt to encircle and seize the city of Sievierodonetsk, one of the last areas under Ukrainian control in Luhansk.

"If the occupiers think that Lyman or Sievierodonetsk will be theirs, they are wrong," the Ukrainian president said in his nightly video address. "Donbas will be Ukrainian."