Belarus' exiled opposition leader visits Kyiv as the city recovers from Russia’s largest missile attack of the year. World leaders are closely watching Belarus' potential support for Russia's invasion. Last week, Russia and Belarus held joint nuclear drills, raising concerns about a new front in northern Ukraine. French President Emmanuel Macron spoke with Belarusian President Alexander Lukashenko on Sunday about the war. Russia warns of more "systemic strikes" on Kyiv. Meanwhile, Ukrainian President Volodymyr Zelenskyy urges international support for air defense. The situation remains tense as diplomatic efforts continue.