Zelensky later confirmed that Russia was carrying out new offensive operations in the area. Washington "is working around the clock" to provide Ukraine with defense supplies, Kirby said.U.S. President Joe Biden authorized earlier on May 10 a $400 million military aid package for Kyiv, which includes artillery shells, air defense missiles, armored vehicles, and other munitions."It is certainly possible that the Russians are setting themselves up for a larger assault on Kharkiv," Kirby said, citing signs that Russia appears to be preparing to use long-range fire within the range of the city.Kirby also said that Russia may achieve some advances in the coming weeks, but breakthroughs are unlikely as the influx of U.S. assistance will help Ukraine withstand the attacks, AFP reported.