(CNN) The US intends to buy 100,000 rounds of artillery ammunition from South Korean arms manufacturers to provide to Ukraine, a US official said, as part of a broader effort to find available weaponry for the high-intensity battles unfolding in Ukraine.
As part of the deal, the US will purchase 100,000 rounds of 155mm howitzer ammunition, which will then be transferred to Ukraine through the US.
The arrangement allows South Korea to stick to its public pledge that it would not send lethal aid to Ukraine. In a statement issued Friday morning, the South Korean Defense Ministry said it had not changed its position on shipping weapons to Ukraine, and that it believed the "end user" of the ammunition is the United States.
"Negotiations are ongoing between the US and Korean companies to export ammunition, in order to make up for the shortage of 155mm ammunition inventories in the US," the ministry said. The Pentagon said in a statement it has been "in discussion" about "potential sales" of ammunition by the US from South Korea.
But statements from South Korea and the US make clear that the deal, which has been in the works for months, has not yet been finalized. The purchase of such a large supply of artillery ammunition is highly sensitive for South Korea, especially given the recent missile launches and weapon tests conducted by North Korea.
South Korea has taken part in meetings of the Ukraine Defense Contact Group, the multi-national group set up by the United States to identify available stockpiles of weapons and ship them to Ukraine. But Seoul has so far publicly refused to send lethal aid to Ukraine, only delivering non-lethal and humanitarian aid, such as medical supplies and bulletproof vests.
News of the transfer, first reported by the Wall Street Journal, comes as the US has warned that North Korea is secretly supplying Russia with artillery shells for the war in Ukraine. The intended transfers from both Pyongyang and Seoul highlight the pressure the war has put on the defense industrial bases of US and Russia.
"There's no question that it's put pressure on our own stockpiles," said Colin Kahl, Under Secretary of Defense for Policy, speaking to reporters at a virtual meeting of George Washington University's Project for Media and National Security. "It's put pressure on our own industrial base. That's been true of our allies."
Since the early months of the war, artillery has been one of the key weapons provided to Ukraine in its fight against Russian forces. The Ukrainian military previously relied on Soviet-era 152mm artillery pieces, but as that ammo supply ran dry, the US and Western countries transitioned them to NATO-standard 155mm howitzers. To date, the US has sent in 142 of these artillery pieces.
The challenge has been the supply of ammunition as the war nears its 9-month mark.
"[The war] has revealed that we have work to do to make our defense industrial base more nimble, more responsive, more resilient," Kahl said.
The US has sent nearly one million rounds of 155mm ammo to Ukraine in recent months. Last week, a defense official said Ukraine is going through 4,000 to 7,000 rounds of artillery ammunition per day, while Russia is firing approximately 20,000 rounds.
Although the main focus is now on air defense systems to protect Ukraine against Russian UAVs and missiles, artillery remains critical to the fight on the ground.
Officials emphasized that the deal between the US and South Korea would not affect the readiness of either country.
In a statement, the Pentagon said South Korea has a "world-class defense industry which regularly sells to allies and partners, including the US."
The US "has been in discussions about potential sales of ammunition to the United States by the South Korean non-governmental industrial defense base," said Lt. Col. Martin Meiners. The Pentagon would not comment on details of the discussions, including specific numbers or timelines.
In August, South Korean President Yoon Suk Yeol said he wanted to make the country one of the world's top weapons suppliers. Yoon's goal is to make Seoul the fourth-largest supplier in the world, behind only the United States, Russia and France. Though South Korea has been willing to provide weapons to Europe -- in July, it signed its largest arms deal to provide Poland with tanks, artillery, and fighter jets -- it has so far refused to sell or deliver weapons directly to Ukraine.