KYIV, Ukraine — Ukraine’s army has retreated from a neighborhood in the outskirts of Chasiv Yar, a strategically important town in the eastern Donetsk region that has been reduced to rubble under a monthslong Russian assault, a military spokesperson said Thursday.

Chasiv Yar is a short distance west of Bakhmut, which was captured by Russia last year after a bitter 10-month battle. For months, Russian forces have focused on capturing Chasiv Yar, a town which occupies an elevated location. Its fall would put nearby cities in jeopardy, compromise critical Ukrainian supply routes and bring Russia closer to its stated aim of seizing the entire Donetsk region.