For Ukrainian gun commander Oleksandr Kozachenko, the long-awaited U.S. ammunition can¡¯t come fast enough as he and his comrades struggle to hold off relentless Russian attacks.

His unit¡¯s U.S.-supplied M777 howitzer, which once hurled 100 shells a day at the encroaching enemy, is now often reduced to fewer than 10.

¡°It¡¯s a luxury if we can fire 30 shells.¡±