Ukrainian forces are in a “difficult” situation near the town of Chasiv Yar where Russia is concentrating its operations, the Ukrainian military announced today.

Moscow has been making progress on the front in recent months, putting even more pressure on Kiev, which is running short of ammunition from its Western allies.

“The situation regarding Chasiv Yar is difficult and tense, and this is not the first day” that this has happened, said Oleh Kalashnikov, the spokesman for the 26th Artillery Brigade. “Today it is at the center of the enemy’s aggressive actions. (Russian forces) are trying to break through our defenses to reach Chasiv Yar,” he explained.

According to Kalashnikov, Russia is intensifying the use of powerful remote-controlled bombs in this zone and “launching them into residential areas and our fortified positions.”

Ukraine has been defending itself for many months due to a lack of ammunition. The $60 billion in aid promised by Washington has been blocked by Congress amid political infighting between Republicans and Democrats.

The commander of Ukraine’s ground forces said on Friday that a 100,000-strong spring offensive by Russia was “possible”, commenting that this would be the “worst-case scenario”.