Ukraine will not leave Russia’s recent hefty attacks against it unanswered, Ukrainian President Volodymyr Zelensky said in his evening video address on Monday. “The terrorist must pay the most for the damage caused by terror, and Russia will pay,” he said. Four people were killed and 45 others injured in the Kharkiv, Zaporizhzhya and Khmelnytskyi regions, as well as in Zelensky’s home region of Krywyj Rih on Monday. In addition, negotiations with international partners in the coming weeks will focus on strengthening Ukraine’s air defence, Zelensky said. “Many steps will be taken and I am confi…