After exchanging a lot of flak on-and-off the track, reigning MotoGP World Champion Jorge Lorenzo said here on Tuesday that it depends on teammate and rival Valentino Rossi if their relationship is to improve.

The Yamaha colleagues have had a difficult relationship in 2015 which worsened after Italian Rossi accused Honda’s Spanish riders Marc Marquez and Dani Pedrosa of helping their compatriot Lorenzo to win the World Championship.

"Before the Malaysian Grand Prix (in October) the relation among the racers was good but then Rossi said that Marquez is helping me to win and he kept saying that," said the three-time World Champion.

"Because of that, I got attacked on social media, especially from Italian fans. I have no problem with Rossi. If he wants to come and talk to me, I will willingly talk to him. It is on him!"

Malaysia was the penultimate race of the year. Six-time champion Rossi was leading the standings ahead of the final race — Valencian Community GP — by seven points but a victory by 28-year-old Lorenzo earned the Spaniard the title.

Lorenzo, who has had 39 MotoGP victories, said that Rossi acts as a stimulant for him to perform better, adding that it is a boon for Yamaha to have two riders of such high quality which helped them to win the constructors’ title for the first time since 2010.

"It is always better to have the best riders because there is a better chance of winning the constructors’ championship. If one rider is good and the other is not then you lose out on winning the title," said the Palma-born.

"Valentino for me is great as a teammate because he acts as this stimulant to do even better and raise the level of competition. It is very good for Yamaha if they have two riders winning them points and races."

The Spaniard, who has 137 MotoGP races under his belt, added that 2015 has been the toughest season of his career but he expects 2016 to be tougher.

"This has been my toughest season yet. 2013 was also quite tough which I lost at the end to Marquez by only four points. I have been extremely focussed this year, tried not to make mistakes and maintained the racing line," said Lorenzo.

"About next year, nothing can be said. It will be tougher than this year and more competitive. Valentino will be fighting for the championship then Pedrosa and Marquez will also challenge us. Suzuki and others could also be fast next season so you never know."