The chief executive of the world's largest PR company made the comments follows protests sparked by recent police brutality against black people in the US. Over the weekend a number of brands - including Nike, Adidas, Netflix, Amazon and Ben & Jerry's - posted on social media in support of the protestors.
Protests have intensified in recent days across the US, and in other countries including the UK, following the death of African American George Floyd by a Minneapolis police officer last week.
In a post on the agency's website entitled "Time for Brands to Step Up", Edelman highlighted a $25m dontation made by Lowe's - the home improvement retailer run by African-American CEO and president Marvin Ellison - to fund minority-owned small business.
"Brands have a fundamental responsibility to join this discussion and to be part of the solution," said Edelman.
"Most brands are reflections of our culture. To do that today means being brave enough to contribute to the change we need to see in culture and society. That means taking on these issues and being part of creating tangible solutions. Above all, to make progress, not promises."
He also pointed to two Unilever brands, both Edelman clients, for "leading in this space": Shea Moisture, which has created a fund for small businesses owned by women of colour; and Ben & Jerry’s, which has supported the NGO Color of Change calling for criminal justice reform, as well as having a "values-led" hiring process removing barriers to employment.
Edelman added: "Consumers are holding brands accountable for their actions and expect them to deliver on the promises and pledges they are making. Two-thirds of consumers globally now self-identify as belief-driven buyers. They are exercising brand democracy, supporting those products that stand with them on important issues. One-third of consumers have changed to products that distinguished themselves during the worst of the COVID-19 lockdown. Brands must continue to communicate but must also offer solutions instead of selling."
Regarding his own company, the CEO stated: "We will also commit to supporting more local NGOs across America as we have done with Project Hood in Chicago, with a financial commitment of pro bono time equivalent to that which we are giving to the Gun Safety Alliance.
"I promise that we will hire more diverse senior executives within the next year, to continue to change the face of our company in service of our clients. To all Edelman, Zeno and UEG employees - black and all races - know that I stand with you in condemning injustice, that I dream of an America that embraces the best of the human spirit."
Edelman said that during a virtual meeting with employees on Friday to discuss the recent events, he was "particularly moved by a young woman who spoke of post-traumatic slave syndrome and her continued concern about the personal safety of her male friends and family members, and her own security in an America at war with itself".
"Our most senior African American executive, [US chief operating officer] Lisa Ross, spoke passionately about the need for Edelman to do better in its hiring and promotion of diverse talent in order to ensure that we have a voice in the ongoing discussion and to expand our impact."