"Just yesterday, President Biden informed his G7 counterparts that the United States will support a joint effort to train Ukrainian pilots on fourth generation fighter aircraft, including F-16s," Sullivan said on Friday.
The Biden administration official went on to detail that insiders have yet to establish a timeline on looming training sessions.
"I am not going to put a time table on how long the training will take," Sullivan told reporters. "That will get worked out through military experts."
In regards to actually providing the military jets, Sullivan indicated it was far too early to say when exactly the highly-desired multirole fighter aircraft would be handed over to Ukrainian forces.
"Our view is that where the F-16 fits into the fight is not right now," Sullivan said, adding that the US and its allies, as Ukrainian pilots are trained to fly the F-16s, will decide which countries will supply these aircraft to Kiev and in what number.
Sullivan took the opportunity to also reiterate during the briefing that the capabilities provided to Ukraine is based on the proposition that the US does not enable or support attacks on Russian territory.
The latest comments from the Biden White House come a day after US media reported that Washington had been "unconvinced" Ukraine needed the aircraft, and that any potential training wold be limited to "technical language and tactical lessons."
Sullivan's remarks also come on the heels of leaked Air Force documents that indicated the US might be able to train Ukrainian pilots on F-16s within a span of four months, opposed to the earlier 18-month timeline that had been voiced by Colin Kahl, the former undersecretary of defense for policy.