Biden assailed Putin in a speech he delivered in Warsaw on Tuesday, following his surprise visit to Ukraine, marking a year after the Russian president launched the invasion into the country. Biden said Putin had gravely underestimated Ukraine by assuming that it would swiftly crumble and its democratic allies would disperse as Russian forces advanced. Biden noted that Putin has presided over a series of humiliating defeats since the start of the invasion.

“One year ago, the world was bracing for the fall of Kyiv,” Biden told an audience of thousands gathered outside the Royal Castle in Warsaw on Tuesday. “Well, I’ve just come from a visit to Kyiv and I can report, Kyiv stands strong. Kyiv stands proud. It stands tall. And most important, it stands free.”

“When President Putin ordered his tanks to roll into Ukraine, he thought we would roll over,” he added. “He was wrong! The Ukrainian people are too brave. America, Europe, a coalition of nations from the Atlantic to the Pacific — we were too unified. Democracy was too strong. Instead of an easy victory he perceived and predicted, Putin left with burned-out tanks and Russian forces in disarray.”

Biden, however, did not address Putin’s decision to “suspend” the New START treaty in the speech, which was filled with triumphant messaging.

Within his first month in office, Biden reached an agreement with Putin to extend New START for five years. (It had been set to expire in February 2021, after the Trump administration failed to hammer out an agreement.) Just last year, the U.S. and Russia committed to creating a new agreement “to achieve deeper, irreversible, and verifiable reductions in their nuclear arsenals,” according to a joint statement.