Mercedes driver Nico Rosberg has warned Lewis Hamilton that he has not given up hope of claiming the Formula 1 title this season.

The 30-year-old trails his teammate by 48 points heading into this weekend's Russian Grand Prix.

Rosberg has had to make do with being second best of late, having also finished behind Hamilton in 2014, but he insists that this year's championship is far from over.

"I'm not backing down and in my mind it's not over yet," he is quoted as saying by BBC Sport. "The gap on Lewis is quite big.

"But the way the whole team has performed this year - from the factories to the garage - has been just incredible. I have the car I need to get back to the top step."

Rosberg has won three races so far this year compared to Hamilton's eight.