Ukraine’s military is confronting a “critical” situation in the country’s northeast, facing troop shortages as it tries to repel a Russian offensive that has been advancing for several days, a top Ukrainian general said on Monday.

Russian troops surged across the border last week to open a new line of attack near Kharkiv, Ukraine’s second-largest city after Kyiv, capturing at least nine settlements and villages and forcing thousands of civilians to flee.

“The situation is on the edge,” Gen. Kyrylo Budanov, the head of Ukraine’s military intelligence agency, said in a video call from a bunker in Kharkiv. “Every hour this situation moves toward critical.”

His bleak assessment echoed those of other Ukrainian officers in recent days, that the country’s military prospects were dimming. In addition to being outnumbered, the Ukrainians face critical shortages of weapons, especially artillery ammunition, and $60.8 billion worth of arms from the United States — approved three weeks ago after months of congressional gridlock — has barely begun to arrive.

Like most Ukrainian officials and military experts, General Budanov said he believes the Russian attacks in the northeast are intended to stretch Ukraine’s already thin reserves of soldiers and divert them from fighting elsewhere.