Lewis Hamilton has said "now is not the time to be silent" and explained why he criticised Formula One as he set out to rally the sport against racism.

In a video released by Mercedes' parent company Daimler on the eve of this weekend's belated season-opening Austrian Grand Prix, the six-time world champion made clear that his comments were not directed at any rival Formula One drivers.

"People perceived it as if I was targeting drivers," said Hamilton of his criticism of those who remained silent and did not speak out against racism.

"But I really wasn't. It was targeted at the whole industry. And it's been something I've been aware of for a long, long time --and I've not really seen anyone doing anything about it.

"People being silent is something that I've experienced for such a long time -- and now is not the time to be silent.

"This is a time to help spread the message, the time to pull together. We need as many voices as we can to push for change."

Hamilton and his Mercedes team-mate Valtteri Bottas will wear black overalls and race in a black liveried car this season following Mercedes move to back the efforts for greater diversity in motorsport.

The Mercedes cars, famously known as the "silver arrows", will be emblazoned with the team's "End Racism" message.

Following the killing of George Floyd last month, Hamilton said: "I see those of you who are staying silent, some of you the biggest of stars, yet you stay silent in the midst of injustice."

His comments were followed by statements from rival F1 drivers, backing the Black Lives Matter movement and condemning racism, and this weekend is expected to see all of the drivers on the grid kneel before Sunday's race.