As organizers behind Friday's Global Climate Strike reported that four million children and adults attended marches and rallies all over the world—making it the biggest climate protest ever—they assured leaders who have been reticent to take bold climate action that the campaigners' work is far from over.

The Global Climate Strike was just the first day in a week of public actions ahead of the U.N. Climate Action Summit.

We've been tracking reported crowd counts at #ClimateStrike events worldwide. 4 MILLION people and counting have walked out of school, work, or home today. We're not through. More actions are coming this week. THANK YOU. Together we will build a world that works for all of us. — 350 dot org (@350) September 20, 2019

On Saturday, the group shared images of more demonstrations being held in countries including Kenya, France, and Indonesia.

4/ WOW 15,000 on the streets of Lyon today as the #ClimateStrike continues. Looks like there are going to be BIG numbers out across France today. https://t.co/5zeTf46vsH — 350 dot org (@350) September 21, 2019

3/ Right now, forest fires in Indonesia are stretching into Malaysia and polluting the air - but it didn't stop over 1,000 people at their #ClimateStrike today. Young, old, indigenous came from near and far pic.twitter.com/hhIV34IjDT — 350 dot org (@350) September 21, 2019

Young climate action leaders who helped to bring the Global Climate Strike to fruition are gathering Saturday at the U.N. in New York for a historic Youth Climate Summit. Sixteen-year-old Greta Thunberg, who held the first one-person climate strike a year ago in Sweden; 17-year-old Xiye Bastida; and 14-year-old Alexandria Villaseñor will speak at the event.

As world leaders attend the U.N. Climate Action Summit on Monday, campaigners are planning dozens of events for the coming week to demand concrete action from policymakers to begin a rapid shift to a renewable energy economy.

350.org, one of the organizations behind the Global Climate Strike, reported late Friday that in the U.S. alone, 600,000 people attended actions in their communities to kick off the week of action. An estimated 300,000 attended the strike in New York City.

Strikes were held in 185 countries, with 1.4 million people walking out of their workplaces and classrooms across Germany and 330,000 attending actions all over Australia.

"Today we saw a movement, made up of people from all ages and backgrounds coming together and calling for the end of coal, oil, and gas," said May Boeve, executive director of 350.org. "September 20th was a demonstration of intent, of 4 million people who took time off from work or school to say that they are ready. Ready to move on and make the changes we need for a future free from fossil fuels and based in climate equity and justice."

"Today's demonstrations mark the beginning of a global mobilization which will span until next Friday, September 27th," Boeve added.