Actors, musicians and other celebrities including Madonna, Beyoncé, Salma Hayek and John Legend have joined together to sign an open letter honoring International Women’s Day on Wednesday, and to warn that recent U.S. government appointments have put decades of progress for women “at risk.”

“We have reached a critical moment in history,” the letter on behalf of Global Citizen and Chime for Change reads. “Recent legislation and rhetoric have put decades of progress for girls and women at risk.”

“All over the world, women are on the frontlines fighting for our future. Yet millions of girls and women are still denied basic equal rights. And recent policies and appointments in the United States jeopardize its position as a global leader and positive role model on human rights,” the letter continues.

The brief letter also urges activists to work hard or else see a “generation’s worth of hard-won gains reversed.”

The letter was signed by numerous celebrities and well-known personalities, including the band Coldplay, actresses Julia Roberts, Frieda Pinto, Jada Pinkett-Smith and Dakota Johnson, Gucci CEO Marco Bizzarri and Huffington Post founder Arianna Huffington.

Dozens of celebrities took to social media Wednesday to mark the day, which also featured a nationwide anti-Donald Trump protest called “A Day Without a Woman.” Hollywood agency UTA and TV networks MTV and Fusion were just a few of the media entities participating in the daylong “strike,” which was organized by many of the same left-wing activists behind January’s anti-Trump Women’s March on Washington.

Read the celebrity-endorsed open letter in full below.

We have reached a critical moment in history. Recent legislation and rhetoric have put decades of progress for girls and women at risk. In 2013, we joined with CHIME FOR CHANGE to convene, unite and strengthen the voices speaking out for girls and women around the world. Today, we find ourselves under threat of seeing a generation’s worth of hard-won gains reversed. All over the world, women are on the frontlines fighting for our future. Yet millions of girls and women are still denied basic equal rights. And recent policies and appointments in the United States jeopardize its position as a global leader and positive role model on human rights. We stand together to say, in a voice louder than ever, that fighting for gender equality is the emergency and the opportunity of our time. With every generation, our story has spread wider, become more familiar. The voices telling it braver, more powerful. But our story is far from over. This is about hearing a call – to join us wherever you are. About raising an alarm – drawing attention where there is work to be done. And about celebrating – those who are already showing us, against impossible odds, what is possible. We believe that connection empowers us. That every voice matters. That each one of us is needed to achieve change. We believe we can do extraordinary things when we come together. We fight for education. For health. For justice. For every girl. Every woman. Everywhere. We fight for our future. Because none of us can move forward if half of us are held back. Join us, and take action for gender equality at globalcitizen.org/IWD2017

Follow Daniel Nussbaum on Twitter: @dznussbaum