Ukraine's military is burning up Soviet-era ammunition that suits earlier systems as it begs the West to deliver additional heavy equipment.
Multiple people familiar with US and Western intelligence say Russia's war in Ukraine is reaching a crucial point that might decide its long-term conclusion.
This key time might compel a painful choice from Western nations, who have supported Ukraine at a cost to their economy and armament stocks.
US Defense Secretary Lloyd Austin will convene a working group of roughly 50 nations to address the issue on Wednesday.
Ukrainian leaders are frustrated that key armaments are seeping into the conflict piecemeal and believe Western support may be waning.
The Russians will either reach Slovyansk and Kramatorsk or be stopped here. If the Ukrainians can hold the line against so many troops, that will matter."