Biden makes unannounced trip to Kyiv first sitting US president to visit active war zone

President Biden makes a secret trip to Kyiv, Ukraine, traveling by overnight train from Poland in the predawn hours with strict secrecy. He meets with President Volodymyr Zelensky and pledges an additional $500 million in military aid including artillery ammunition. Air raid sirens sound during their joint walk through the city. Biden calls the visit a "demonstration that the United States stands with Ukraine." It is the first time a sitting American president has visited a capital city in an active war zone that is not protected by US military forces. The White House coordinated with Russia in advance to inform them of Biden's presence in Ukraine to avoid military incidents.