Barack Obama speaks at the Sept. 11 memorial observance ceremony at the Pentagon on Sept. 11. | AP Photo Obama preaches unity at 9/11 Pentagon memorial

President Barack Obama preached unity at a 9/11 memorial service at the Pentagon in Virginia on Sunday.

"The most enduring memorial to those we lost, is ensuring the America that we continue to be. That we stay true to ourselves. We stay true to what's best in us. That we do not let others divide us," Obama said.


Nearly 3,000 were killed on Sept. 11, 2001, in New York, rural Pennsylvania, and at the Pentagon after groups of Al Qaeda terrorists hijacked four airplanes and crashed them in those locations. The attacks prompted multiple wars in the Middle East over the past 15 years, as well as an ever-spiraling series of ideological battles, some of which have led to terrorist attacks in the United States and elsewhere around the globe.

During the ceremony, the president touched on the continued fight against groups like Al Qaeda and how terrorists are trying to spread "hateful ideologies" to get people to "commit unspeakable violence."

"We've mourned the loss of innocence from Boston to San Bernardino to Orlando," Obama said. "Groups like Al Qaeda, like ISIL, know they will never be able to defeat a nation as great and as strong as America. So instead, they try to terrorize in the hopes that they can still get enough fear that we turn on each other."

"That's why it is so important today that we reaffirm our character as a nation of people drawn from every corner of the world, every color, every religion, every background."

Obama went on to say that the U.S. is known for diversity and that Americans should not see it as a weakness, but instead as the country's "greatest strength." He said it is the "America that we must remain true to."

"May God bless memory of the loved ones here and across the country, they remain in our hearts today," Obama ended his speech. "May He watch over, these faithful families and all who protect us. And may God forever bless the United States of America."