Drone footage taken on April 10, 2022, shows Mariupol’s Drama Theater destroyed during the fierce fighting for the city and shows the extent of the devastation to the building and the surrounding area. READ MORE: The presidents of Poland, Lithuania, Latvia and Estonia – all NATO countries bordering Russia – visited Kyiv on Wednesday to show support a day after Russian President Vladimir Putin vowed to continue Moscow’s offensive against Ukraine until its “full completion.” The leaders of the four countries, all worried that Russia could attack them if Ukraine were to fall to Moscow, traveled by train to the Ukrainian capital to meet with Ukraine President Volodymyr Zelenskyy. While failing to capture Kyiv and much of Ukraine, Russian forces have bombarded numerous cities, killed thousands of Ukrainian civilians and destroyed housing and hospitals before Moscow pulled back its forces from western Ukraine. A U.S. Defense Department official said Russia is regrouping its forces, including helicopters and artillery systems, in Belarus for a “renewed push” targeting eastern Ukraine. While acknowledging it has sustained a “significant” loss of troops, Moscow claimed Wednesday that more than 1,000 Ukrainian troops had surrendered in the besieged port of Mariupol. The information could not be verified, however. U.S. President Joe Biden for the first time on Tuesday called Russia’s attack on Ukraine “a genocide” and contended that “Putin is just trying to wipe out the idea of even being a Ukrainian.”