"The 11th year, for me, it's the same as if it happened yesterday. It could be 50 years from now, and to me, it'll be just as important as year one, or year five or year ten."
Political leaders still are welcome to attend the ground zero ceremony, and they are expected at the other commemorations, as well.
The Obamas planned later to visit wounded soldiers at Walter Reed Army Medical Center. The U.S. terror attacks were followed by wars in Afghanistan and Iraq, where the U.S. military death toll years ago surpassed the 9/11 victim count. At least 1,987 U.S. troops have died in Afghanistan and 4,475 in Iraq, according to the Pentagon.
Allied military forces marked the anniversary at a short ceremony at NATO's headquarters in Kabul, Afghanistan with a tribute to more than 3,000 foreign troops killed in the decade-long war.
"Eleven years on from that day there should be no doubt that our dedication to this commitment, that commitment that was seared into our souls that day so long ago, remains strong and unshaken," said Marine Gen. John Allen, the top commander of U.S. and coalition troops.
Scores gathered at the Flight 93 National Memorial in western Pennsylvania, where the fourth hijacked plane crashed into a Pennsylvania field. Biden and Secretary of the Interior Ken Salazar are expected to speak at the ceremony for the flight's 40 victims.
Other ceremonies were held across the country — from New York's Long Island, where hundreds wrote messages to their loved ones on a memorial, to Boston, where more than 200 people with ties to Massachusetts were remembered. But some cities scaled back — the suburb of Glen Rock, N.J., where 11 people were killed, did not hold a memorial this year for the first time.
In New York, officeholders from the mayor to presidents have been heard in the past, reading texts ranging from parts of the Declaration of Independence and the Gettysburg Address to poems by John Donne and Langston Hughes.
For former New York Gov. George Pataki, this year's change ends a 10-year experience that was deeply personal, even as it reflected his political role. He was governor at the time of the attacks.
"As the names are read out, I just listen and have great memories of people who I knew very well who were on that list of names. It was very emotional." But the former governor supports the decision not to have government figures speak. "It's time to take the next step," he said.
The National Sept. 11 Memorial and Museum — led by Mayor Michael Bloomberg as its board chairman — announced this summer that this year's ceremony would include the words of family members, hoping to remember the dead and honor families "in a way free of politics" in an election year, memorial President Joe Daniels said.
But others said keeping politicians off the rostrum smacked of ... politics. And several said they were unwilling to let go.
"Coming here, it's like ripping off a Band-Aid," said Yasmin Leon, whose sister was killed at the trade center. "You rip it off and the wound is opened again. But you keep coming back anyway."
Leon said there was a sense of closure this year because last year, the Sept. 11 memorial — twin reflecting pools surrounded by victims' names — opened to the public. "This year, we're just here to reflect," she said.
The Sept. 11 museum was initially to open this year, but is on hold for at least another year after a monthslong dispute over financing between the foundation and the government agency that owns the site. Late Monday, Bloomberg and New York Gov. Andrew Cuomo announced an agreement that paves the way for finishing the $700 million-plus project "as soon as practicable."
Before the deal, Cuomo, a Democrat, and New Jersey Gov. Chris Christie, a Republican, had called on federal officials to give the memorial a financial and technical hand. Some victims' relatives saw the no-politicians anniversary ceremony as retaliation.
"Banning the governors of New York and New Jersey from speaking is the ultimate political decision," said one relatives' group, led by retired Deputy Fire Chief Jim Riches. His firefighter son and namesake was killed responding to the burning World Trade Center.
Associated Press writers Verena Dobnik and Alex Katz in New York and Amir Shah in Afghanistan contributed to this report.
Follow Jennifer Peltz at http://twitter.com/jennpeltz
- Pistorius shown in TV interview ahead of...
- Obama names Stonewall national monument; 1st...
- Sanders says he'll vote for Clinton, but no...
- Items owned by gangster 'Whitey' Bulger to be...
- Motivational speaker Robbins' coal walk burns...
- Lucas abandons plan to build museum in...
- World doping watchdog shuts down Rio Olympic...
- Officials: No evidence Orlando gunman was gay
- House Republicans' report faults Obama... 51
- In need of help, Trump finds few... 39
- Big ruling for abortion rights in... 36
- The pro-life plan that could reverse... 36
- Did Trump really just become a... 36
- Love won't go to GOP national convention 35
- Supreme Court abortion decision could... 31
- Will 'Brexit' vote help Trump in Utah? 26