A top White House official confirmed on Sunday that the Biden administration urged against the transfer of fighter jets from Poland to Ukraine because the deal involved the vehicles being transferred through a US airbase, Independent reported.

White House national security adviser Jake Sullivan was speaking on NBC’s Meet the Press, and he pointed to the potential risks posed by flying offensive weaponry to Ukraine from the US’s Ramstein Air Base in Germany.

"The cost/benefit analysis did not justify flying fighter planes from a U.S. base in Germany into contested airspace in Eastern Europe,” Sullivan said.

“But [President Joe Biden] also directed us to double down on our effort to get the Ukrainians advanced capabilities that could achieve a similar purpose,” he continued.

Other US officials including military commanders have explained their opposition to the deal by contending that Ukraine’s military does not need additional fighter jet aircraft, a position strongly contested by Ukraine’s own government. A distinction has arisen concerning whether MiG-29 aircraft should be considered offensive or defensive weaponry, given the potential for their use to strike targets in Russia.

 “The transfer of MiG-29 aircraft will not appreciably increase the effectiveness of the Ukrainian Air Force,” said General Tod Wolters, head of US Europe Command. He also contended: “Adding aircraft to the Ukrainian inventory is unlikely to change the effectiveness of the Ukrainian Air Force relative to Russian capabilities.”

Their statements come into direct conflict with requests from Ukraine’s government, which has pushed the US to supply the country with aircraft or allow other NATO allies to do so.