Biden pledges new Ukraine aid, warns Russia on chem weapons

  • President Joe Biden, left, talks with French President Emmanuel Macron and Briitish Prime Minister Boris Johnson, right, as they arrive at NATO Headquarters in Brussels, Thursday, March 24, 2022. (Brendan Smialowski, Pool via AP)

  • NATO Secretary General Jens Stoltenberg, center front left, U.S. President Joe Biden, center front, and British Prime Minister Boris Johnson, front right, pose during a group photo during an extraordinary NATO summit at NATO headquarters in Brussels, Thursday, March 24, 2022. As the war in Ukraine grinds into a second month, President Joe Biden and Western allies are gathering to chart a path to ramp up pressure on Russian President Vladimir Putin while tending to the economic and security fallout that's spreading across Europe and the world. (AP Photo/Thibault Camus)

  • British Prime Minister Boris Johnson, front right, looks toward U.S. President Joe Biden, front left, at a group photo during an extraordinary NATO summit at NATO headquarters in Brussels, Thursday, March 24, 2022. As the war in Ukraine grinds into a second month, President Joe Biden and Western allies are gathering to chart a path to ramp up pressure on Russian President Vladimir Putin while tending to the economic and security fallout that's spreading across Europe and the world. (AP Photo/Thibault Camus)

  • President Joe Biden arrives for a meeting of the G7 Leaders’ at NATO Headquarters in Brussels, Belgium, on Thursday. (Doug Mills/The New York Times via AP, Pool)

  • President Joe Biden speaks during a news conference after a NATO summit and Group of Seven meeting at NATO headquarters, Thursday, in Brussels. (AP Photo/Evan Vucci)

BRUSSELS — President Joe Biden and Western allies pledged new sanctions and humanitarian aid on Thursday in response to Vladimir Putin’s assault on Ukraine, but their offers fell short of the more robust military assistance that President Volodymyr Zelenskyy pleaded for in a pair of live-video appearances.