Russia-Ukraine War Day 4: Ukrainian forces put up fierce resistance to slow the advance of the larger and more powerful Russian military closing in on the capital, as the U.S. and EU rushed ammunition and weapons to Kyiv and announced powerful new financial sanctions aimed at further isolating Moscow. A senior U.S. defense official said more than half of the Russian combat power that was massed along Ukraine’s borders had entered the country. The curfew forcing everyone in Kyiv inside was set to last through Monday morning. Meanwhile, the U.S., European Union and United Kingdom agreed to block “selected” Russian banks from the SWIFT global financial messaging system, which moves money around more than 11,000 banks and other financial institutions worldwide, part of a new round of sanctions aiming to impose a severe cost on Moscow for the invasion. They also agreed to impose ”restrictive measures” on Russia’s central bank.