Russia launched an intense drone and missile attack on Kyiv and other Ukrainian cities overnight, killing a mother and her son in the capital, amid faltering U.S.-backed attempts to broker a pause in the fighting.

Ukrainian President Volodymyr Zelenskyy announced that Ukraine was ready to accept a U.S. proposal for a 30-day cease-fire, provided Russia did the same.

But Russia's preferred deep-strike weapon — the Shahed drone — has gotten some major upgrades since the start of the year, including jet engines and Starlink satellite attachments, putting pressure on Ukraine's already strained air defense.