Russia launched a massive attack on Ukraine's Kharkiv, killing four and injuring dozens. President Zelenskyy condemned the violence and appealed for urgent air defense assistance.

The attacks come days after Trump says Putin had "very strongly" promised response to Ukraine "Spider web" attack.

The United States believes that Russian President Vladimir Putin's threatened retaliation against Ukraine over its drone attack last weekend has not happened yet in earnest and is likely to be a significant,