President Obama visted the Pentagon today to remember the 15th anniversary of the September 11th terrorist attacks and the "3,000 beautiful lives" that were cut short. 

"We wonder how their lives might have unfolded -- how their dreams might have taken shape," the president said.

The president continued to address survivors and families of victims, "Even as you've mourned, you've summoned the strength to carry on."

Obama continued to say that terrorist groups like ISIS will "never be able to defeat a nation as strong as America" so they operate to instill fear and separation to change the way Americans live. "We know that our diversity, our patchwork heritage, is not a weakness," the president said. "This is the America that was attacked that September morning. This is the America that we must remain true to."

Watch Obama's remarks below:

Our thoughts are with all of those whose loved ones lost their lives in the attacks, and while defending this country in the years since.