Nico Rosberg has revealed that his relationship with Lewis Hamilton has "returned to neutral", several years on from their fierce battle for the F1 world title.
Rosberg and Hamilton became friends as they grew up together in karting, before progressing to F1 and sharing the podium for the first time in 2008.
In 2013, their motor racing careers intertwined further when they teamed up at Mercedes, but an initially amicable partnership soon turned sour.
As Mercedes stole a march on their F1 rivals under the 2014 rules reset, Rosberg and Hamilton found themselves in a battle of their own up front.
Hamilton takes two titles, then Rosberg fights back
After Hamilton picked up titles in 2014 and 2015, Rosberg fought back to clinch the 2016 crown in an intense title fight that featured several flashpoints.
According to Rosberg, their relationship broke down as soon as Mercedes developed machinery that could challenge for honours.
"It happened immediately when we were fighting for the World Championship. Not before," he told Eurosport.
"But that's always the case: when you're fighting for success in every race and for titles, it doesn't work anymore."
Asked if there was a particular trigger or event that led to trouble, Rosberg said: "No, it's been a build-up from one race to the next.
"If you want to decide the World Championship for yourself, you can't play 'peace, joy, pancake'. You have to test limits and go into grey areas to win.
"Especially when two drivers are at such a high level, and then it often gets tight."
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Rosberg has "no regrets" over Hamilton fight
One of the 2016 flashpoints was a dramatic collision at the Spanish Grand Prix, eliminating both drivers from the race.
But six years on from the drama, Rosberg made clear: "I don't regret anything. It was a sensational time and a mega fight. I'm very proud of that.
"In the meantime, we've returned to [a] neutral [relationship], which is okay."
Rosberg and Hamilton have recently rekindled their rivalry in Extreme E, an electric off-road series aimed at promoting climate awareness.
Rosberg's team secured honours in the inaugural 2021 campaign after a fittingly close battle with Hamilton's outfit.
"We didn't know about each other's plans beforehand; we built up our racing teams in parallel," Rosberg added.
"We also announced our teams within a couple of weeks [of each other], which was totally cool, [and] it's great that we're reviving this duel."
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