(REUTERS) - Four-time Formula One world champion Sebastian Vettel, who moved from Red Bull at the end of last year, said on Thursday he hoped Ferrari could become the strongest challengers to Mercedes this season.

"It depends how strong and dominant Mercedes will start into the season," said the German, speaking at a sponsor's event.

"It is expected that they will be very strong. But for the pack behind them it will be very tense.

"I hope that we are there and establish ourselves in the mid- to long-term this season as the second force. That would be a huge step forward."

Mercedes' double world champion Lewis Hamilton and Nico Rosberg are widely expected to dominate again this year with the Briton winning 11 races and his teammate five last season.

The Silver Arrows have looked ominous in testing before the Australian Grand Prix, which begins the season in Melbourne on March 15.