The four-time champion, the last non-Mercedes driver to win the championship, finished behind Rosberg in Sunday's Abu Dhabi Grand Prix, and insisted there is no doubt that his compatriot is a deserving champion.
"I think, in my point of view, you don't win the championship by luck," said Vettel. "Nico won the championship. He's a deserved champion. You collect a lot of points throughout the season."
"Sometimes you might have fortunate situations [or] unfortunate situations with your car, but I think there have been other situations in the past with other drivers, that's the way it goes," he continued. "Sometimes you have better years in this regard, sometimes worse years, but I think it was Nico's day and it's a sign of respect and greatness to give him that."
"I think we owe it to him, he's a deserved champion."
Bahrain International Circuit - Winter testing