Senior Ukrainian officials visited Washington on Tuesday to seek U.S. support against Russia while accusing Moscow of dragging its feet at peace talks. Kyiv showed its ability to continue fighting by setting off an explosive device under a bridge that has become a symbol of the Kremlin's claims on Ukrainian territory.

Ukraine President Volodymyr Zelenskyy has condemned a Russian attack on the city center of Sumy, saying that's all one needs "to know about Russia’s ‘desire’ to end this war.”

Russian forces are advancing in the northern Ukrainian region of Sumy, bringing the regional capital within range of their drones and artillery, according to Ukrainian officials and analysts.