Western governments are mobilizing their arms manufacturers to boost production and replenish stocks severely depleted by supplying Ukraine with supplies for the six-month struggle against Russian invasion.

US Secretary of Defense Lloyd Austin this week announced a meeting of senior national arms directors from allied countries to make long-term plans for supplying Ukraine and rebuilding its own weapons reserves.

“They will discuss how our defense industrial bases can best equip Ukraine’s future armed forces with the capabilities they need,” he said at a meeting of the Ukraine Contact Group at Ramstein Air Force Base in Germany, which includes 50 countries currently involved support the war effort.

On Friday, Pentagon weapons procurement chief Bill LaPlante said the meeting would take place on September 28 in Brussels.

The goal is to determine “how we can continue to work together to increase production of key functions, resolve supply chain issues, and increase the interoperability and interchangeability of our systems,” LaPlante told reporters at the Pentagon.

Not all NATO countries have the same weapons, but their weapons are compatible. This allows ammunition made in one Atlantic Alliance country to be used by another.

At the beginning of the war, the Ukrainian military mainly used weapons and ammunition that met Russian standards. But within months these were exhausted – particularly in crucial artillery and missile systems – and it became increasingly dependent on Western allies with NATO-standard weapons.

But that, in turn, dragged down large amounts of ammunition that the Allies had been storing for their own defense.

Rebuilding these supplies is now critical.

In July, the European Union announced 500 million euros for joint purchases over the next two years to replenish arms supplied to Kyiv.

The priority is more anti-tank and anti-aircraft missile systems, as well as 155mm artillery pieces and ammunition.

EU countries “have used their stockpiles of ammunition, light and heavy artillery, anti-aircraft and anti-tank systems and even armored vehicles and tanks,” EU Commissioner Thierry Breton said at the time.

“This has created a de facto vulnerability that needs to be addressed urgently now,” he warned.

The United States, Ukraine’s top defense supplier since the start of the war, has pledged $15.2 billion worth of weapons, including Javelin anti-tank missiles, artillery and ammunition compatible with NATO weapons.

The Pentagon has shipped about 800,000 155mm artillery shells to Ukraine, while the United States has only one factory that makes them, the General Dynamics plant in Scranton, Pennsylvania, which produces just 14,000 rounds a month.

“We have plans…to do that in increments of up to 36,000 per month in about three years,” LaPlante said.

But that would bring annual output to just over half what Washington gave Ukrainians in less than six months.

The Pentagon wants allies to ramp up their own production lines to replenish inventories.

The US military recently announced a series of new contracts with arms manufacturers inside and outside the United States to do this.

It includes $364 million for 250,000 rounds of multi-manufacturer 155mm artillery ammunition, $624 million for Stinger anti-aircraft missiles, $324 million for Javelin anti-tank missiles, and millions more for other weapon systems, ammunition and defense equipment.

Dave Butler, spokesman for the Pentagon’s joint chiefs of staff, said the decision would be guided by US manufacturing capabilities but not specifically determined.

“Ukraine’s need for a specific weapon is the deciding factor,” he said.