Ferrari is still "together" even amid waves of rumours and Sebastian Vettel's failure to win the drivers' world championship.

That is the claim of team boss Maurizio Arrivabene, after Mercedes' Lewis Hamilton wrapped up his fifth crown in Mexico.

"It's a horrible moment," German Vettel admitted amid Hamilton's title celebrations.

Both Vettel and Arrivabene warmly congratulated Hamilton, but the message was clear: amid rumours of internal problems at Ferrari, the Maranello team remains together.

"We do not give up," Italian Arrivabene told Sky Italia.

"The constructors' championship is still open, we have taken more points in that and do not give up until the end."

As for Vettel's disappointment, Arrivabene suggested that while the German has been criticised for mistakes in the second half of the season, Ferrari still supports him.

"You have to be close to him in down moments like this, we do not leave him alone," he said.

"We must be strong and throw everything behind him, go forward and do not give up. We have proved we are together even if the others are saying otherwise. So let's keep going," Arrivabene said.

As for Mercedes, Arrivabene sounded reluctant to talk much about the German team.

"I do not talk about the others. We closed on them in the last two races, then I leave the judgement to you," he said.

"Congratulations to Hamilton, but now let's play for the constructors. It will be difficult but we will not give up."