A Ukrainian serviceman carries a 155 mm artillery shell before firing at Russian positions from a U.S.- supplied M777 howitzer in Kharkiv region, Ukraine, Thursday, July 14, 2022 (AP Photo/Evgeniy Maloletka)

US Army Secretary Christine Wormuth told The Washington Post that Ukrainian forces fire in just two days during heavy clashes what the US produces during one whole month of 155 mm howitzer rounds.

The secretary added that despite increasing production by the defense industry, the maximum capacity that can be produced currently is around 14,000 155 mm howitzer artillery rounds in a span of a month.

Kiev's firepower is highly dependent on the US government-funded weapons being pushed to the front lines on an almost weekly basis.

The news outlet also reported that the "initial war supply operation" was not made to go on for long periods, adding that the ongoing fight in Ukraine has uncovered weaknesses in the US's "strategic planning for its own future battles," and unveiled serious flaws in the "American and NATO defense industrial base."

The report warned stocks of many critical weapons are near depletion and production time for new missiles might take months or even years.

Earlier this month, EU foreign policy chief Josep Borrell said that the EU had run out of military stockpiles as it provided Ukraine with an overwhelming amount of military support.

"This war has also been a wake-up call for all of us about our military capabilities. We have given weapons to Ukraine, but in so doing, we realised that our military stockpiles have been depleted. With conventional war returning to the heart of Europe, we also realized that we are lacking critical defense capabilities, to be able to protect ourselves from a higher level of threats on the European continent itself," he said in a statement.

Pentagon planners are being faced with an important question as the US continues to supply Ukraine amid its war that has no end sight and which could last years: If another major war were to erupt today, would the United States have enough munition in its stockpiles to hold its ground?

While Russia is firing around 20,000 rounds per day, ranging from bullets for automatic rifles to truck-sized cruise missiles, Ukraine is firing back around 7,000 rounds per day, including 155 mm howitzer rounds, Stinger anti-aircraft missiles, NASAMS air defense munitions, and thousands of small rounds.