President Obama spoke of a "9/11 generation" that answered the country's call to duty following the attacks 13 years ago today. In remarks from the Pentagon, the president remembered those who died in the attacks and all the men and women who have given their lives since that day.

"Over more than a decade of war, this 9/11 generation has answered our country's call. And three months from now our combat mission in Afghanistan will come to an end. Today we honor all who have made the ultimate sacrifice these 13 years. More than 6,800 American patriots. And we give thanks to those who serve in harm's way to keep our country safe and meet the threats of our time. America endures in that perennial optimism that defines us as a people," said Obama.

He noted that starting tomorrow, there will be teenagers who were born after the 9/11 attacks.

"While these young Americans did not know the horrors of that day, their lives have been shaped by all the days since."

Obama said the country has refused to live in fear since that fateful day, turning each 9/11 anniversary into "something that those who attacked us could never abide."

"We visit our great cities. We fill our stadiums and cheer for our teams. We carry on because as Americans, we do not give in to fear ever."

Watch the president's full speech above.