"Star Wars" actor rallied crowds at a large London protest against George Floyd's death on Wednesday, telling demonstrators that "now is the time" to demand racial equality.

The star made an emotional speech into a megaphone as thousands poured through Hyde Park, marching in solidarity with protesters in the U.S.

"Black lives have always mattered," Boyega said at the rally. "We have always been important. We have always meant something. We have always succeeded regardless. And now is the time. I ain't waiting. I ain't waiting."

"Every black person understands and realizes the first time you are reminded that you are black," Boyega added, occasionally stopping to fight back tears during the speech. "You remember. Every black person in here remembers when another person reminded you that you were black."

Crowds braved bad weather to gather for the central London protest, following the lead of activists who have in response to Floyd's killing at the hands of a Minneapolis police officer.

The British-Nigerian actor listed the names of several black men killed by police in the United States, and also those of Stephen Lawrence -- a black British teenager murdered in a racially motivated attack in 1993 -- and Mark Duggan, whose 2011 shooting by police sparked protests and then riots across the U.K.

"This is so vital," Boyega said. "I need you guys to understand how painful this s**t is."

"It is very, very important that we keep control of this movement, and we make this as peaceful as possible," he added. "They want us to mess up."

And he went on to address black men specifically, urging them to "take care of our black women."

Protesters have been taking part in , both in solidarity with the American protesters and to highlight racism in their own countries.