 Live from NPR News in Washington, I'm Lakshmi Singh. President Biden is reaffirming U.S. commitments to Ukraine's defense against Russia at the NATO summit. I want you to know we're going to be with you every step of the way. But Biden's reelection prospects loom large over the international gathering. He's due to close the summit with his first press conference since last month's shaky debate performance, which has since led to a wave of calls among allies for Biden to step aside. NPR's Windsor Johnston has more.