Mark Parker, CEO of Nike Inc., wrote an open letter condemning President Donald Trump’s executive order to halt immigration from certain Muslim countries and promising to support brand endorser Mo Farah.

Farah, a four-time Olympic gold medal-winning long-distance runner for Great Britain, is a Muslim born in Somalia, one of the countries  under Trump’s 90-day ban. Farah is currently training in Ethiopia and is concerned thta he will not be able to return to Oregon, where he livecs, while the ban is in effect.

“It’s deeply troubling that I will have to tell my children that Daddy might not be able to come home — to explain why the President has introduced a policy that comes from a place of ignorance and prejudice,” Farah wrote on Facebook.

Parker’s letter reads, in part, “Today, I’m thinking of everyone who is impacted, like Sir Mo Farah. … What Mo will always have — what the entire Nike family can always count on — is the support of this company. We will do everything in our power to ensure the safety of every member of our family: our colleagues, our athletes and their loved ones.”

“Nike believes in a world where everyone celebrates the power of diversity. Regardless of whether or how you worship, where you come from or who you love, everyone’s individual experience is what makes us stronger as a whole,” Parker added. “Those values are being threated by the recent executive order in the U.S. banning refugees, as well as visitors, from seven Muslim-majority countries. This is a policy we don’t support. And I know we’re all asking what this means for our future, for our friends, our families and our broader community.”

Parker’s entire letter was posted on the Instagram account of Nike Basketball Brand Manager Jian Allen although it’s been taken down.