Two US-made F-16 fighters in the air during an scramble take off at the eastern Hualien air force base on January 23, 2013.
Washington CNN  — 

The US will allow European countries to train Ukrainians on F-16 fighter jets, a top Biden administration official confirmed Sunday, a potential boon for Ukraine’s efforts to counter Russia’s air superiority.

“The president has given a green light and we will allow, permit, support, facilitate and in fact provide the necessary tools for Ukrainians to begin being trained on F-16s, as soon as the Europeans are prepared,” national security adviser Jake Sullivan told CNN’s Jake Tapper on “State of the Union.”

The decision cements a stark turnaround for President Joe Biden, who said earlier this year that he did not believe that Ukraine needed the F-16s. One of the main issues Kyiv’s ground forces have faced as their counteroffensive gets underway is Russian air power holding them back. Russia still maintains air superiority, which makes it difficult for ground forces to advance.

In May, Biden had informed G7 leaders that the US would support a joint effort with allies and partners to train Ukrainian pilots on fourth generation aircraft, including F-16s, though it was unclear at the time when that training would star.

The US-made jet has air-to-air refueling capabilities and is compatible with most NATO weapons already being supplied to Ukraine. Despite first entering production in the 1980s, it has gone through several upgrades, making it more advanced and versatile that any jet Ukraine currently has in its fleet, and a fierce rival for most Russian aircraft, with the exception of newer models that Moscow has hesitated to deploy in Ukraine.

Sullivan noted Sunday that European allies have said they need several weeks to prepare training abilities and that the US would meet whatever timeline they set out.

“The United States will not be the hold-up in ensuring that this F-16 training can get underway,” he said.

Turning to US national defense, Sullivan lamented the House-passed defense policy bill that includes the adoption of several controversial amendments that touched on hot-button social issues.

“This legislation is never getting to the president’s desk because what you’ve seen from an extreme group of Republicans is to put forward a set of amendments that try to mix domestic social debates with the needs the security needs,” Sullivan said.

The addition of amendments pushed by conservative hard-liners related to abortion policy and transgender health care access as well as targeting diversity and inclusion programs infuriated Democrats – and will now set up a clash with the Democratic-controlled Senate.

Pressed to acknowledge that the bill was passed along party lines but supported by a majority of House GOP lawmakers, Sullivan argued that the process had been hijacked by a, “small group of Republicans.”

“A huge number of folks in the House, including Republicans, in my view, are not particularly interested in having politics come into the middle of the (National) Defense Authorization Act,” Sullivan said, referring to the official name of the defense policy bill.

“So it was a small group of Republicans who essentially created a trap. A circumstance we don’t need to find ourselves in.”

CLARIFICATION: This story and headline have been updated to better describe the Ukrainian F-16 trainees.

CNN’s Natasha Bertrand, Vasco Cotovio, Frederik Pleitgen, William Bonnett and Daria Markina Tarasova contributed to this report.