fighting in eastern ukraine. as our correspondent, andrew harding reports from the front line, ukraine s army is struggling with a shortage of ammunition and other military supplies and is urging the us to help out. ukrainian tanks heading into battle. we are close to the russian lines here and to a town the kremlin has been desperate to capture for months. gunfire. inside of avdiivka, it s not going well for ukraine. these troops are increasingly pinned down and struggling. gunfire. in the ditch here, a wounded soldier needing urgent help. so what s going wrong for ukraine after two years of war? a simple answer can be found a few kilometers away. a ukrainian artillery team. last year, these men were firing 80 shells a day at russian positions around avdiivka. not any more. so these are the last two shells that you have? yes , says the officer in charge. and these two don t even work. it is an alarming situation. russia is now outgunning ukraine by perhaps five to one.