"[Biden] originally decided against sending [Abrams tanks] because his military told them that they would not be useful on the battlefield in this fight,” Sullivan said in an interview on ABC’s “This Week.”

What would be useful, Sullivan said, were Germany’s Leopard tanks. But after German officials told the White House they would not send those alone, Biden changed his mind.

“So, in the interest of alliance unity and to ensure that Ukraine got what it wanted, despite the fact that the Abrams aren’t the tool they need, the president said, ‘OK, I’m going to be the leader of the Free World. I will send Abrams down the road if you send Leopards now.’ Those Leopards are getting sent now,” Sullivan said.