U.S. President Barack Obama says the decade that followed the September 11 terrorist attacks shows “a story of resilience” for the United States.

Speaking on the 10th anniversary of the attacks that killed nearly 3,000 people, the President said the U.S. “took a painful blow, and emerged stronger.” He said the nation showed its resolve to defend its citizens and way of life.

Mr. Obama said the Pentagon is now repaired, a new memorial and tower are taking shape at the former site of the World Trade Center, and people in the U.S. continue to work in skyscraper offices, travel on crowded public buses and subways, and live full lives without succumbing to fear. He said the U.S. has also held strong to its core values of equality, democracy, free speech, and freedom of religion, instead of using the threat of further attacks to clamp down.

The speech, delivered at “A Concert for Hope” event in Washington , caps off a full day of solemn tributes.

Events were held at each of the sites attacked a decade ago — in New York City, the Pentagon outside Washington, and Shanksville, Pennsylvania.

Mr. Obama, leading the nation in remembrances of the tragic anniversary, made a somber tour of all three sites.

In New York, he and predecessor George W. Bush walked through the recently finished memorial at the site of the World Trade Center. Both presidents participated in a ceremony in which family and loved ones read the names of the thousands who were killed when two hijacked jetliners struck the north and south towers of the Trade Center.

Mr. Obama later traveled to Shanksville, Pennsylvania where he and first lady Michelle Obama laid a wreath in honor of the 40 lives lost when Flight 93 crashed into a field outside the rural town. The president and his wife greeted the victims' loved ones and visited the memorial wall inscribed with each passenger and crew member's name.

Sunday afternoon, the president laid a wreath at the Pentagon memorial commemorating the 184 victims of Flight 77's crash into the massive Defense Department headquarters. While hymns played quietly, Mr. Obama and his wife visited with the victims' families gathered at the memorial .

Sunday's ceremonies have been marked by moments of silence. In New York, attendees fell quiet at 8:46 a.m. and again at 9:03 a.m. when each of the planes struck the twin towers ten years ago. Attendees later paused to remember when each of the towers fell, and they listened quietly as family and loved ones of the victims read the names of those killed.

After the first moment of silence in New York, President Obama read a Bible passage that speaks of God as refuge and strength. After the second moment of silence, former president Bush read a letter of support from Abraham Lincoln to a mother who had lost all five of her sons in America's Civil War.

The Pentagon observed its moment of silence at 9:37 a.m. local time. At the Pentagon, Vice President Joe Biden spoke of the bravery of first responders and those who joined the military after September 11, 2001, serving in the subsequent wars in Afghanistan and Iraq and other dangerous areas. Defense Secretary Leon Panetta said the events of September 11 have since strengthened and inspired the country.