In a formal resolution adopted in 2005 (full text), the United Nations General Assembly designated January 27 each year as International Holocaust Remembrance Day. That date is the anniversary of the 1945 liberation of Auschwitz-Birkenau. The United Nations has posted a calendar of events that will mark this year's commemoration. The United States Holocaust Museum will also be streaming programming to mark the day.
UPDATE: President Biden also issued a statement (full text), saying in part:
Today, we join together with people from nations around the world to commemorate International Holocaust Remembrance Day by remembering the 6 million Jews, as well as the Roma and Sinti, Slavs, disabled persons, LGBTQ+ individuals, and many others, who were murdered by the Nazis and their collaborators during the Shoah. We must never forget the truth of what happened across Europe or brush aside the horrors inflicted on our fellow humans because of the doctrines of hatred and division....
The United States will continue to champion justice for Holocaust survivors and their heirs. We are committed to helping build a world in which the lessons of the Holocaust are taught and in which all human lives are valued.