Rosberg claimed his maiden world title with a second-place finish in Sunday's season-ending Abu Dhabi Grand Prix despite Hamilton claiming a fourth straight race victory.
But the German conceded relations with Hamilton "will always remain difficult".
"We're rivals. But the fact we've known each other since childhood helps in the difficult periods," Rosberg told reporters in his hometown of Wiesbaden.
He was asked several times about Hamilton's tactics, with the Briton slowing down towards the end of the race while blocking Rosberg in the hope two other drivers -- Sebastian Vettel and Max Verstappen -- could catch and overtake him.
"I find it a shame that we're talking about that so much. I can also understand Lewis, he's a fighter, the world title was at stake. One can understand sometimes overstepping the limits when you're fighting for the world title."
Rosberg also refused to expand on how he would have reacted had he been in Hamilton's place, with the Briton needing to win and see his rival finish off the podium to snatch the title.
"It's too hypothetical. For me, there's no sense in talking about this story," Rosberg said.