President Biden underlined the United States’ ongoing support for Ukraine during a weekend call with President Volodymyr Zelensky, as well as efforts to strengthen Kyiv’s air defenses against tactical strikes by Russia on civilian infrastructure. Biden vowed during the call to hold Russia accountable for war crimes and atrocities, and impose “costs on Russia for its aggression,” according to an official White House readout. He welcomed Zelensky’s stated openness to a “just peace.”