Ukrainian air defense units are actively working to repel a Russian airstrike on Kyiv, with explosions reported by Reuters as intercepts occur. The U.S. has temporarily closed its embassy in the capital due to credible threats of a significant aerial attack expected on November 20. U.S. citizens are advised to prepare for immediate sheltering if an air raid alarm is announced. Sirens have been activated in Kyiv and other regions, indicating a heightened threat level.