Ukraine is running out of ammunition for its U.S.-supplied howitzers, as Congress withholds additional U.S. aid for its armed forces, and Russia rapidly bolsters its firepower, Kiev soldiers warned.

A Ukrainian artillery team operating an M109 Paladin howitzer said they have been forced to start rationing their shells to try to repel Russian forces near Bakhmut due to dwindling supplies.

“We cannot fulfill our tasks 100%, although we want to,” a commander of the 93rd Mechanized Brigade told CNN, adding that he is desperately waiting for more ammunition.

“My crew and other crews are waiting for you and are ready to work 24 hours a day,” he said.

The crew ended up receiving a new shipment of ammunition for their howitzer during CNN’s time with the soldiers, but the supply only included four additional rounds, which were not explosives.

Another Ukrainian commander stationed in Bakhmut acknowledged that Russia’s war economy is rapidly outstripping Ukraine’s own supplies from its allies, with Moscow drawing on its Soviet-era reserves as it attacks the border.

“The ratio is approximately 10 to 1,” the commander told the media outlet regarding the ammunition disparity between soldiers from both countries. “Russia is a country that produces ammunition, and they have strategic reserves. Yes, they use old Soviet systems. But Soviet systems can still kill.”

Even the head of NATO pressed this point on Tuesday, warning that the war has become “a battle of ammunition.”

“Increased ammunition production is an absolute necessity for us to continue providing support to Ukraine,” NATO Secretary General Jens Stoltenberg said in a statement Tuesday.

“So far we have drawn on our reserves, but with the ammunition consumption we see in Ukraine and the needs we see to continue supporting Ukraine, we need to increase production, and that is exactly what NATO allies are doing,” Stoltenberg said – noting that the group has signed related contracts worth $10 billion since July.

Earlier this month, Ukrainian Major General Vadym Skibitskyi stated that Russia was manufacturing up to 130 long-range missiles and 115 shorter-range rockets per month.

Ukrainian intelligence services also reported that Moscow had increased its projectile production to about 2 million rounds a year.

Meanwhile, Ukraine is lagging behind, with the Pentagon last month announcing the shipment of $250 million worth of weapons to Kyiv, the latest batch of U.S. military aid as Congress dithers on approving additional aid.

President Biden asked Congress in October to approve $61.4 billion in additional security aid for Ukraine as part of a $106 billion emergency funding request, but an aid package has yet to be approved.

The lack of American aid was highlighted by a German intelligence report warning that Russia would take advantage of this disparity to launch an all-out attack on Ukraine in the coming weeks.

Norwegian General Eirik Kristoffersen also warned Sunday that Moscow is increasing its weapons arsenal at a much faster pace than previously anticipated, widening the gap with Ukraine and threatening the spread of war to the rest of Europe.

Kristoffersen added that NATO needs to get ahead of Moscow, which he said has moved into a “war economy” that is rapidly strengthening with allies in Iran and North Korea.

Ronny Reyes