The U.S. is not currently considering sending F-16 warplanes to Ukraine, national security adviser Jake Sullivan said Sunday, doubling down on comments President Joe Biden made Friday.

“You don’t think [Zelenskyy] needs F-16s now?” ABC’s David Muir asked Biden in an interview at the White House on Friday.

“No, he doesn’t need F-16s now,” Biden responded.

Sullivan elaborated on the president’s comments Sunday, saying the United States is “taking a very hard look at what it is that Ukraine needs for the immediate phase of the war that we’re in.” Right now, those needs include “tanks, infantry fighting vehicles, armored personnel carriers, artillery, tactical air defense systems” Sullivan said — but not the advanced warplanes Ukraine has requested.

“F-16s are a question for a later time,” Sullivan said during an interview on CNN’s “State of the Union.” “And that’s why President Biden said that, for now, he’s not moving forward with those.”

When pressed by CNN’s Dana Bash about whether that means the U.S. ruling out sending F-16s later on, Sullivan reiterated Biden’s Friday comments.

“What President Biden said is what goes across the administration. And he was very clear. He said: ‘I’m ruling them out for now.’”

Rep. Michael McCaul (R-Texas) argued Sunday that the Biden administration shouldn’t wait, since Ukraine has “a window of time” to launch a successful counteroffensive that could soon close.

“When we slow-walk and slow-pace this thing, it drags it out,” he said on ABC’s “This Week.”