It made sense to Zuko, who's clearly already inclined toward forgiveness, but indeed, needs time to sort it out. So he just nods, and pats his uncle on the back affectionately. Hey, for Zuko, that's a lot. He can only give so many hugs.

"Thank you, Uncle. I'm sorry. But thank you."

He meets Iroh's gaze with an earnest expression, the sincerity at least clear in his voice. Zuko can take a ball and run with it. But he's quite conscious by this point that in all this sordidness... Iroh's hurting, too. And for once, he wants to be there for his uncle, too, even as Iroh's trying so hard to be there for him.

Okay, okay, maybe one more hug. He's a lot more physical than he once was after half a year on a touch-based planet, okay — and he loves his uncle!