The White House is working on a deal to transfer Slovakian S-300 systems to Ukraine, according to a top Biden administration official. 

“We are working with Slovakia to identify the requirements for meeting their needs,” said Celeste Wallander, Assistant Secretary of Defense for International Security Affairs, during a House Armed Services Committee hearing on Wednesday. “We are working on this, and meanwhile we have focused on getting countries that hold Soviet legacy systems, including S-300 systems―that have spare parts, missiles, different parts of that S-300―who are willing to send [them] to Ukraine,” Wallander added.

Ukrainian president Volodymyr Zelensky asked Washington to provide Ukraine’s armed forces with S-300 surface-to-air missile (SAM) systems during an address to Congress several weeks ago. Slovakian defense minister Jaroslav Nad offered to “immediately” supply Ukraine with S-300 units if NATO could backfill Slovakian missile defense capabilities with a system of similar capabilities. Bulgaria and Greece, the other two NATO members that possess the S-300, have been hesitant to directly supply Ukraine with what is a major strategic weapons system.

Ukrainian defense minister Oleskii Reznikov previously asked for Patriot PAC-3 SAM systems from Washington, but the request was denied. As per Defense One, U.S. defense officials contend that Ukrainian personnel have not been trained on these systems; any Patriot systems in Ukraine would have to be operated by U.S. troops, a clear breach of the Biden administration’s pledge not to put U.S. forces on the ground in Ukraine. Moreover, the system is expensive to maintain and has not been integrated into Ukraine’s existing radar networks.

Ukraine’s long-range air defenses consist largely of older, Soviet-era S-300 SAM systems. Though precise figures are difficult to come by, Ukraine is widely believed to have possessed around 100 of these systems on the eve of the Russian invasion on February 24. The Russian military claimed to have destroyed around forty Ukrainian S-300 systems in the invasion’s opening stages, dealing a potentially crippling blow to Ukraine’s defenses against cruise missiles and aircraft.

Top Kremlin officials declared “total air superiority” in Ukraine on the fifth day of the invasion, but those claims have been widely disputed in the West. It remains unclear to what extent Russia controls Ukrainian airspace; U.S. defense officials have said that some of the war’s most devastating airstrikes, including the Yavoriv training facility attack, were initiated from Russian territory. Nevertheless, recent reports suggest that the invading forces have at least secured limited air superiority in regions of Ukraine where the Russian military has been able to consolidate control.

Mark Episkopos is a national security reporter for the National Interest.

Image: Reuters.