The leaders of Ukraine and the United States will hold talks weeks after President Trump agreed to participate in postwar security guarantees for Ukraine.

© Alina Smutko/Reuters

The gains could help counter Moscow’s narrative that Russian advances are unstoppable and that Kyiv should settle for a peace deal, even if it means giving up territory.

© Brendan Hoffman for The New York Times

Ukrainian and European officials, analysts and entrepreneurs keep asking privately, what’s up with Trump?