President Joe Biden delivered a message Friday about the terrorist attacks on September 11th just ahead of the 20th anniversary and talked about how Americans must have “unity.”

“20 years after September 11, 2001, we commemorate the 2,977 lives we lost and honor those who risked and gave their lives,” Biden tweeted to his millions of followers. “As we saw in the days that followed, unity is our greatest strength. It’s what makes us who we are — and we can’t forget that.” (RELATED: Biden Orders Declassification Review Of Sept. 11 Documents)

POTUS post also included a video message praising those who showed courage on the day of the attack and every single day since. (RELATED: Families Affected By 9/11 Ask Biden Not To Come To Memorial Events: REPORT)

WATCH:

20 years after September 11, 2001, we commemorate the 2,977 lives we lost and honor those who risked and gave their lives. As we saw in the days that followed, unity is our greatest strength. It’s what makes us who we are — and we can’t forget that. pic.twitter.com/WysK8m3LAb

— President Biden (@POTUS) September 10, 2021

“In the days that followed September 11th, 2001, we saw heroism everywhere,” the president explained. “In places expected and unexpected. We also saw something all too rare, a true sense of national unity. Unity and resilience, the capacity to recover and repair in the face of trauma.”

“Unity and service, the 9/11 generation stepping up to serve and protect in the face of terror to get those terrorists who were responsible, to show everyone seeking to do harm to America that we will hunt you down and we will make you pay,” he added. “That will never stop.”

“Today, tomorrow, ever from protecting America,” Biden continued. “Yet we also witnessed the darker forces of human nature. Fear and anger, resentment and violence against Muslim Americans, true and faithful followers of a peaceful religion.

POTUS explained that “unity is the one thing that must never break” and said it “unity is what makes us who we are.”

Biden also shared that, for him, the lesson of September 11th is “that at our most vulnerable” the U.S. can find its “greatest strength” through “unity.”

In conclusion, the president said “we must not be afraid” and “may God protect our troops.”